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ব্যাংক নিয়োগ প্রস্তুতি ⎯ লং কোর্স

পরীক্ষাব্যাংক নিয়োগ প্রস্তুতি ⎯ লং কোর্সতারিখতারিখ অনির্ধারিতসময়45 minutes২৪ বৈধ · অসম্পূর্ণ
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Math - 05 - Time & Work, Chain Rule
ঘনত্ব
উত্তর
উত্তরিতবর্তমানপুনরায় দেখুনঅসম্পূর্ণ

ব্যাংক নিয়োগ প্রস্তুতি ⎯ লং কোর্স

ব্যাংক নিয়োগ প্রস্তুতি ⎯ লং কোর্স · তারিখ অনির্ধারিত · ২৫ প্রশ্ন

.
If A and B can together do a work in 15 days and B alone can finish the job in 20 days. In how many days, A alone can finish the job?
  1. ক) 60
  2. খ) 45
  3. গ) 40
  4. ঘ) 30
  5. ঙ) None of above
সঠিক উত্তর:
ক) 60
উত্তর
সঠিক উত্তর:
ক) 60
ব্যাখ্যা

A and B complete a work in = 15 days
One day's work of (A + B) = 1/15
B complete the work in = 20 days;
One day's work of B = 1/20
Then, A's one day's work = 1/15 - 1/20
= (4 - 3)/60
= 1/60
Thus, A can complete the work in = 60 days.

.
X can do a piece of work in 40 days. He works at it for 8 days and then Y finishes it in 16 days. How long will they together take to complete the work?
  1. ক) 13(1/3) days
  2. খ) 15 days
  3. গ) 20 days
  4. ঘ) 26 days
  5. ঙ) None of Above
সঠিক উত্তর:
ক) 13(1/3) days
উত্তর
সঠিক উত্তর:
ক) 13(1/3) days
ব্যাখ্যা

Work done by X in 8 days = 1/40 x 8 = 1/5
Remaining work = 1 - 1/5 = 4/5

Now, 4/5 work is done by Y in 16 days.
Whole work will be done by Y in = 16 x 5/4 = 20 days.
X's 1 day's work = 1/40
Y's 1 day's work = 1/20
(X + Y)'s 1 day's work = 1/40 + 1/20 = 3/40

Hence, X and Y will together complete the work in = 40/3 = 13(1/3) days.

.
4 men and 6 women can complete a work in 8 days, while 3 men and 7 women can complete it in 10 Days. In how many days will 10 women complete it?
  1. ক) 10 days
  2. খ) 20 days
  3. গ) 30 days
  4. ঘ) 40 days
  5. ঙ) 50 days
সঠিক উত্তর:
ঘ) 40 days
উত্তর
সঠিক উত্তর:
ঘ) 40 days
ব্যাখ্যা

(4M + 6W) × 8 = (3M + 7W) × 10
=> M / W = 11 : 1
Now , (4 × 11 + 6 × 1) × 8 = 10 × 1 × T
=> T = 40 days

.
P can complete a work in 12 days working 8 hours a day. Q can complete the same work in 8 days working 10 hours a day. If both P and Q work together, working 8 hours a day, in how many days can they complete the work?
  1. ক) 5(5/11)
  2. খ) 5(6/11)
  3. গ) 6(5/11)
  4. ঘ) 6(6/11)
  5. ঙ) None of these
সঠিক উত্তর:
ক) 5(5/11)
উত্তর
সঠিক উত্তর:
ক) 5(5/11)
ব্যাখ্যা

P's 1 day 1 hrs work = 1/96 part.
Q's 1 day 1 hr's work = 1/80 part.
P & Q together work in 1 hr per day = 1/96 + 1/80 = 11/480 part.
P & Q together completes in 8 hr per day = 11×8/480 = 11/60 part.
So, days required = 60/11 = 5(5/11)

.
A is 30% more efficient than B. How much time will they, working together, take to complete a job which A alone could have done in 23 days?
  1. ক) 11 days
  2. খ) 13 days
  3. গ) 20(3/17) days
  4. ঘ) 15 days
  5. ঙ) None of these
সঠিক উত্তর:
খ) 13 days
উত্তর
সঠিক উত্তর:
খ) 13 days
ব্যাখ্যা

Ratio of times taken by A and B = 100:130 = 10:13
Suppose B takes x days to do the work.
Then,
10:13 :: 23:x
⇒ x = (23 × 13)/10
⇒ x = 299/10
A's 1 day's work = 1/23
B's 1 day's work = 10/299
(A + B)'s 1day's work = 1/23 + 10/299
= 23/299
= 1/13
∴ A and B together can complete the work in 13 days.

.
Robi and Kamal are working on an assignment. Robi takes 6 hours to type 32 pages on a computer, while Kamal takes 5 hours to type 40 pages. How much time will they take, working together on two different computers to type an assignment of 110 pages?
  1. ক) 7 hours 30 minutes
  2. খ) 8 hours
  3. গ) 8 hours 15 minutes
  4. ঘ) 8 hours 25 minutes
  5. ঙ) None of these
সঠিক উত্তর:
গ) 8 hours 15 minutes
উত্তর
সঠিক উত্তর:
গ) 8 hours 15 minutes
ব্যাখ্যা

Number of pages typed by Robi in 1 hour = 32/6 = 16/3 .
Number of pages typed by Kamal in 1 hour = 40/5 = 8
Number of pages typed by both in 1 hour = (16/3 + 8) = 40/3
Therefore, Time taken by both to type 110 pages = 110/(40/3) hours
= 110 × 3/40 hours (or) 8 hours 15 minutes.

.
A takes twice as much time as B or thrice as much time as C to finish a piece of work. Working together, they can finish the work in 2 days. B can do the work alone in:
  1. ক) 4 days
  2. খ) 6 days
  3. গ) 8 days
  4. ঘ) 12 days
  5. ঙ) None of these
সঠিক উত্তর:
খ) 6 days
উত্তর
সঠিক উত্তর:
খ) 6 days
ব্যাখ্যা

Suppose A, B and C take x, x/2, x/3 days respectively to finish the work
Then,
1/x + 2/x + 3/x = 1/2
⇒ 6/x = 1/2
⇒ x = 12
So, B takes 12/2 = 6 days to finish the work.

.
X can do a piece of work in 40 days. He works at it for 8 days and then Y finishes it in 16 days. How long will they together take to complete the work?
  1. ক) 13(1/3)days
  2. খ) 15 days
  3. গ) 20 days
  4. ঘ) 26 days
  5. ঙ) None of these
সঠিক উত্তর:
ক) 13(1/3)days
উত্তর
সঠিক উত্তর:
ক) 13(1/3)days
ব্যাখ্যা

Work done by X in 8 days = 1/40×8 = 1/5

Remaining work = 1−1/5 = 4/5

Now, 4/5 work is done by Y in 16 days
Whole work will be done by Y in = 16×5/4 = 20 days
∴ X's 1 day's work = 1/40

∴ Y's 1 day's work = 1/20

(X + Y)'s 1 day's work
=1/40 + 1/20
=3/40

Hence, X and Y will together complete the work in
= 40/3
= 13(1/3) days

.
A can do a piece of work in 10 days, B in 15 days. They work together for 5 days, the rest of the work is finished by C in two more days. If they get Rs. 3000 as wages for the whole work, what are the daily wages of A, B and C respectively:
  1. ক) 200, 250, 300
  2. খ) 300, 200, 250
  3. গ) 200, 300, 400
  4. ঘ) 250, 200, 300
  5. ঙ) None of these
সঠিক উত্তর:
খ) 300, 200, 250
উত্তর
সঠিক উত্তর:
খ) 300, 200, 250
ব্যাখ্যা

A's 5 days work = 50%
B's 5 days work = 33.33%
C's 2 days work = 16.66% [100 - (50 + 33.33)]

Ratio of contribution of work of A, B and C = 50: 33(1/3) : 16(2/3)
= 3 : 2 : 1

A's total share = Tk. 1500
B's total share = Tk. 1000
C's total share = Tk. 500

A's one day's earning = Tk.300
B's one day's earning = Tk.200
C's one day's earning = Tk.250

১০.
A, B, C together can do a piece of work in 10 days. All the three started working at it together and after 4 days, A left. Then, B and C together completed the work in 10 more days. In how many days A can complete the work alone?
  1. ক) 25
  2. খ) 24
  3. গ) 23
  4. ঘ) 21
  5. ঙ) None of these
অনির্ধারিত
ব্যাখ্যা

(A + B + C) do 1 work in 10 days.

So (A + B + C)'s 1 day work = 1/10
And as they work together for 4 days,
so, work done by them in 4 days = 4/10 = 2/5
Remaining work = 1 - (2/5) = 3/5
(B + C) takes 10 more days to complete 3/5 work.
So ( B+C)'s 1 day work = 3/50
Now A's 1 day work = (A + B + C)'s 1 day work - (B + C)'s 1 day work
= 1/10 - 3/50
= 1/25
A does 1/25 work in in 1 day
Therefore 1 work in 25 days.

লাইভ পরীক্ষায় প্রশ্নটি অসম্পূর্ণ ছিলো। প্রশ্নের শেষ লাইনে 'A' এর কথা উল্লেখ ছিলো না। ‘A’ - এর কথা উল্লেখ থাকলে প্রশ্ন ও সমাধান ঠিক ছিলো।

১১.
A works twice as fast as B. If B can complete a work in 18 days independently, the number of days in which A and B can together finish the work is:
  1. ক) 4 days
  2. খ) 6 days
  3. গ) 8 days
  4. ঘ) 10 days
  5. ঙ) None of these
সঠিক উত্তর:
খ) 6 days
উত্তর
সঠিক উত্তর:
খ) 6 days
ব্যাখ্যা

Ratio of rates of working of A and B = 2:1.
So, ratio of times taken = 1:2
Therefore, A's 1 day's work = 1/9
B's 1 day's work = 1/18
(A + B)'s 1 day's work = 1/9 + 1/18 = 1/6
So, A and B together can finish the work in 6 days.

১২.
A is thrice efficient as B and C is twice as efficient as B. What is the ratio of number of days taken by A,B and C, when they work individually?
  1. ক) 2:6:3
  2. খ) 2:3:6
  3. গ) 1:2:3
  4. ঘ) 3:1:2
  5. ঙ) None of these
সঠিক উত্তর:
ক) 2:6:3
উত্তর
সঠিক উত্তর:
ক) 2:6:3
ব্যাখ্যা

A : B : C
Ratio of efficiency - 3 : 1 : 2
Ratio of No. of days - 1/3 : 1/1 : 1/2
or 2 : 6 : 3

১৩.
4 men can repair a road in 7 hours. How many men are required to repair the road in 2 hours?
  1. ক) 17 men
  2. খ) 14 men
  3. গ) 13 men
  4. ঘ) 16 men
  5. ঙ) None of these
সঠিক উত্তর:
খ) 14 men
উত্তর
সঠিক উত্তর:
খ) 14 men
ব্যাখ্যা

4 men can repair a road in 7 hours
1 men can repair a road in 7 × 4hours = 28 hours
28 hours is required by 1 men
2 hours is required by 28/2 men = 14 men

১৪.
A, B and C can complete a piece of work in 24, 6 and 12 days respectively. Working together, they will complete the same work in:
  1. ক) 1/24 days
  2. খ) 7/24 days
  3. গ) 24/7 days
  4. ঘ) 4 days
  5. ঙ) None of these
সঠিক উত্তর:
গ) 24/7 days
উত্তর
সঠিক উত্তর:
গ) 24/7 days
ব্যাখ্যা
(A + B + C)'s 1 day's work = (1/24 + 1/6 + 1/12) = 7/24
so, A, B and C together will complete the work in 24/7 days.
১৫.
When A, B and C are deployed for a task , A and B together do 70% of the work and B and C together do 50% of the work. Who is most efficient?
  1. ক) A
  2. খ) B
  3. গ) C
  4. ঘ) A & B equally efficient
  5. ঙ) Can't be determined
সঠিক উত্তর:
ক) A
উত্তর
সঠিক উত্তর:
ক) A
ব্যাখ্যা

A + B = 70%
B + C = 50%
[∵ (A + B) + (B + C) − (A + B + C) = B]
=> B = 20% ; A = 50% and C = 30%
Hence A is most efficient.

১৬.
A can do a piece of work in 30 days. He works at it for 6 days and then B finishes it in 18 days. In what time can A and B together it?
  1. ক) 14 (1/2) days
  2. খ) 11 days
  3. গ) 13 (1/4) days
  4. ঘ) 12 (6/7) days
  5. ঙ) None of these
সঠিক উত্তর:
ঘ) 12 (6/7) days
উত্তর
সঠিক উত্তর:
ঘ) 12 (6/7) days
ব্যাখ্যা

Let 'B' alone can do the work in 'x' days
6/30 + 18/x = 1
=> x = 22.5
1/30 + 1/22.5 = 7/90
=> 90/7 = 12 (6/7) days

১৭.
If a quarter kg of carrots costs 60 poysa, how many poysa will 200 gms cost?
  1. ক) 78 poysa
  2. খ) 48 poysa
  3. গ) 54 poysa
  4. ঘ) 62 poysa
  5. ঙ) 65 poysa
সঠিক উত্তর:
খ) 48 poysa
উত্তর
সঠিক উত্তর:
খ) 48 poysa
ব্যাখ্যা

Quarter of Kg means 250 gm
Less weight, less price (Direct Proportion)
So, 250 : 200 :: 60 : x
=> x = 48
So 200 gm will cost 48 poysa.

১৮.
In a queue, Shahadat is ninth from the rear end. Altaf's place is eighth from the front. Nitu is standing between the two. What could be the minimum number of boys standing in the queue?
  1. ক) 18
  2. খ) 14
  3. গ) 22
  4. ঘ) 24
  5. ঙ) None of these
সঠিক উত্তর:
খ) 14
উত্তর
সঠিক উত্তর:
খ) 14
ব্যাখ্যা

1 2 3 4 5 6 (Shahadat) 7 (Nitu) 8 (Altaf) 9 10 11 12 13 14
Here, Althaf is 8th from front, Shankar is 9th from rear end and Nitu is between them
So minimum no. of boys standing in the queue = 14.

১৯.
If a person has Tk. 2000 and he wants to distribute this to his five children in the manner that each son has Tk. 30 more than the younger one, what will be the share of the youngest child?
  1. ক) Tk. 175
  2. খ) Tk. 325
  3. গ) Tk. 340
  4. ঘ) Tk. 260
  5. ঙ) Tk. 300
সঠিক উত্তর:
গ) Tk. 340
উত্তর
সঠিক উত্তর:
গ) Tk. 340
ব্যাখ্যা

Assume first child (the youngest) get = Tk. x
According to the question ;
each son having Tk. 30 more than the younger one

Second child will get = Tk. x + 30
Third child will get = Tk. x + 30 + 30 = x + 60
Fourth child will get = Tk. x + 30 + 30 + 30 = x + 90
Fifth child will get = Tk. x + 30 + 30 + 30 + 30 = x + 120

Total amount they got = Tk. 2000

x + (x+30) + (x+60) + (x+90) + (x+120) = 2000
5x + 300 = 2000
5x = 1700
x = Tk. 340
So the youngest child will get Tk. 340.

২০.
A contractor undertakes to do a piece of work in 40 days. He engages 100 men at the beginning and 100 more after 35 days and completes the work in stipulated time. If he had not engaged the additional men, how many days behind schedule would it be finished?
  1. ক) 3
  2. খ) 5
  3. গ) 6
  4. ঘ) 9
  5. ঙ) None of these
সঠিক উত্তর:
খ) 5
উত্তর
সঠিক উত্তর:
খ) 5
ব্যাখ্যা
[(100 × 35) + (200 × 5)]men can finish the work in 1 day.
Therefore, 4500 men can finish the work in 1 day. 100 men can finish it in = 4500/100 = 45 days.
This is 5 days behind Schedule
২১.
A certain number of men can finish a piece of work in 100 days. If there were 10 men less, it would take 10 days more for the work to be finished. How many men were there originally?
  1. ক) 75
  2. খ) 82
  3. গ) 100
  4. ঘ) 110
  5. ঙ) 120
সঠিক উত্তর:
ঘ) 110
উত্তর
সঠিক উত্তর:
ঘ) 110
ব্যাখ্যা

Originally let there be x men.

Less men, More days (Indirect Proportion)

Therefore, (x - 10) : x :: 100 :110

=> (x - 10) × 110 = x × 100
=> x = 110

২২.
3 pumps working 8 hours a day, can empty a tank in 2 days. How many hours a day must 4 pumps work to empty the tank in 1 day?
  1. ক) 9
  2. খ) 10
  3. গ) 11
  4. ঘ) 12
  5. ঙ) 15
সঠিক উত্তর:
ঘ) 12
উত্তর
সঠিক উত্তর:
ঘ) 12
ব্যাখ্যা

Let the required number of working hours per day be x.
More pumps , Less working hours per day (Indirect Proportion)
Less days, More working hours per day (Indirect Proportion)
Pumps 4 : 3 and Days 1 : 2 } :: 8:x
=> (4 × 1 × x) = (3 × 2 × 8)
=> x = 12

২৩.
If the Price of 6 toys is Tk. 264.37. What will be the approximate price of 5 toys?
  1. ক) Tk. 120
  2. খ) Tk. 100
  3. গ) Tk..200
  4. ঘ) Tk. 220
  5. ঙ) None of these
সঠিক উত্তর:
ঘ) Tk. 220
উত্তর
সঠিক উত্তর:
ঘ) Tk. 220
ব্যাখ্যা

Let the required Price be Tk. X .
Then, Lest toys , Less cost (Direct Proportion)
Therefore 6 : 5 :: 264.37 : x
=> 6 × x = 5 × 264.37
=> x = 220.308
Therefore, Approximate price of 5 toys = Tk. 220

২৪.
A fort had provision of food for 150 men for 45 days. After 10 days, 25 men left the fort. The number of days for which the remaining food will last, is:
  1. ক) 29
  2. খ) 37
  3. গ) 42
  4. ঘ) 54
  5. ঙ) 60
সঠিক উত্তর:
গ) 42
উত্তর
সঠিক উত্তর:
গ) 42
ব্যাখ্যা

After 10 days : 150 men had food for 35 days.
Suppose 125 men had food for x days.
Now, Less men, More days (Indirect Proportion)
∴ 125 : 150 :: 35 : x
⇒ 125 × x = 150 × 35
⇒ x = (150 × 35)/125
= 42

২৫.
If 7 spiders make 7 webs in 7 days, then 1 spider will make 1 web in how many days?
  1. ক) 1
  2. খ) 3
  3. গ) 7
  4. ঘ) 14
  5. ঙ) 16
সঠিক উত্তর:
গ) 7
উত্তর
সঠিক উত্তর:
গ) 7
ব্যাখ্যা

Let the required number of days be x.
Less spiders, More days (Indirect Proportion)
Less webs, Less days (Direct Proportion)
Spiders 1:7 and Webs 7:1 } :: 7:x
=> 1 × 7 × x = 7 × 1 × 7
=> x = 7