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ব্যাংক নিয়োগ প্রস্তুতি ⎯ লং কোর্স

পরীক্ষাব্যাংক নিয়োগ প্রস্তুতি ⎯ লং কোর্সতারিখতারিখ অনির্ধারিতসময়35 minutes১৯ 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 · ২০ প্রশ্ন

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A, B, and C completed a work costing Tk 2250. A worked for 6 days, B for 4 days, and C for 9 days. If their daily wages are in the ratio of 5 : 6 : 4, how much will A receive?
  1. ক) 600 Tk
  2. খ) 620 Tk
  3. গ) 750 Tk
  4. ঘ) 800 Tk
ব্যাখ্যা
Question: A, B, and C completed a work costing Tk 2250. A worked for 6 days, B for 4 days, and C for 9 days. If their daily wages are in the ratio of 5 : 6 : 4, how much will A receive?

Solution:
Let the daily wages of A, B, and C be Tk 5x, 6x, and 4x respectively.

Then, ratio of their amounts
=(5x × 6) : (6x × 4) : (4x × 9)
= 30 : 24 : 36
= 5 : 4 : 6

∴A's amount = 2250 × (5/15) = 750 Tk
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A is thrice as good a workman as B and so takes 40 days less than B for doing a job. The time in which they can do the job together is -
  1. ক) 20 days
  2. খ) 15 days
  3. গ) 30 days
  4. ঘ) 24 days
ব্যাখ্যা
Question: A is thrice as good a workman as B and so takes 40 days less than B for doing a job. The time in which they can do the job together is - 

Solution:
Let A alone takes x days 
and B alone takes 3x days to complete the job.

ATQ,
3x - x = 40
⇒ 2x = 40
⇒ x = 20

So, A alone takes 20 days and B alone takes 3 × 20 = 60 days to complete the job.

(A + B)'s 1 days work = (1/20 + 1/60) = 1/15 part

∴ A and B together can do the work in 15 days.
.
3 pumps, working 12 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) 10 hours
  2. খ) 16 hours
  3. গ) 18 hours
  4. ঘ) 20 hours
ব্যাখ্যা
Question: 3 pumps, working 12 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?

Solution:
3 pumps need 2 days by working 12 hours
1 pump needs 1 day by working 12 × 3 × 2 hours
4 pumps need 1 day by working (12 × 3 × 2)/4 hours
= 18 hours
.
If 9 examiners can examine a certain number of answer books in 12 days by working 5 hours a day; for how many hours a day would 4 examiners have to work in order to examine twice the number of answer books in 27 days?
  1. ক) 5 hours
  2. খ) 8 hours
  3. গ) 10 hours
  4. ঘ) 12 hours
ব্যাখ্যা
Question: If 9 examiners can examine a certain number of answer books in 12 days by working 5 hours a day; for how many hours a day would 4 examiners have to work in order to examine twice the number of answer books in 27 days?

Solution:
9 examiners  need 12 days by working 5 hours
1 examiner needs 1 day by working 5 × 9 × 12 hours
4 examiners  need 27 days by working (5 × 9 × 12)/(4 × 27) hours
= 5 hours

So, twice the work need twice time.
∴ So, the answer = (5 ×  2) = 10 hours
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If 6 persons working 8 hours a day earn Tk 9600 per week, then 9 persons working 6 hours a day will earn per week?
  1. ক) 10800 Tk
  2. খ) 12000 Tk
  3. গ) 12400 Tk
  4. ঘ) 12800 Tk
ব্যাখ্যা
Question: If 6 persons working 8 hours a day earn Tk 9600 per week, then 9 persons working 6 hours a day will earn per week?

Solution:
Earning of 6 × 8 = 48 hours is 9600 Tk
Earning of 1 hour is 9600/48 Tk
Earning of 9 × 6 = 54 hours is  (9600 × 54)/48 Tk
= 10800 Tk
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A man completes 2/3 of a job in 12 days. At this rate, how many more days will it take him to finish the
  1. ক) 6 days
  2. খ) 4 days
  3. গ) 3 days
  4. ঘ) 9 days
ব্যাখ্যা
Question: A man completes 2/3 of a job in 12 days. At this rate, how many more days will it take him to finish the job?

Solution:
Rest part of job = 1 - 2/3 = 1/3

2/3 of the work done in 12 days
1 of the work done in (12 × 3)/2 days
1/3 of the work done in (12 × 3)/(2 × 3) days
= 6 days
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A garrison of 400 men had food for 27 days. After 3 days a reinforcement of 200 men arrived. For how many more days will the remaining food last now?
  1. ক) 15 days
  2. খ) 16 days
  3. গ) 20 days
  4. ঘ) 22 days
ব্যাখ্যা
Question: A garrison of 400 men had food for 27 days. After 3 days a reinforcement of 200 men arrived. For how many more days will the remaining food last now?

Solution:
After 3 days, food having for = 27 - 3 = 24 days
After arriving 200 men, total men = 400 + 200 = 600 men

400 men can eat the food for 24 days
1 man can eat the food for 24 × 400 days
600 men can eat the food for (24 × 400)/600 days
= 16 days
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A fort had 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) 36 days
  2. খ) 40 days
  3. গ) 42 days
  4. ঘ) 48 days
ব্যাখ্যা
Question: A fort had 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 -

Solution:
After 10 days, food having for = 45 - 10 = 35 days
After 25 men left, total = 150 - 25 = 125 men

150 men can eat food for 35 days
1 man can eat food for (35 × 150) days
125 men can eat food for (35 × 150)/125 days
= 42 days
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A canteen requires 420 bananas for a week. Totally, how many bananas will it require for the months of January, February, and March in 2024?
  1. ক) 4860
  2. খ) 5000
  3. গ) 5220
  4. ঘ) 5460
ব্যাখ্যা
Question: A canteen requires 420 bananas for a week. Totally, how many bananas will it require for the months of January, February, and March in 2024?

Solution:
January = 31 days
February = 29 days
March = 31 days

Total = 31 + 29 +31 = 91 days

In 7 days the canteen requires 420 bananas
In 1 day the canteen requires 420/7 bananas
In 91 days the canteen requires (420 × 91)/7 bananas
= 5460 bananas
১০.
Some persons can do a piece of work in 24 days. Two times the number of such persons will do half of that work in -
  1. ক) 6 days
  2. খ) 3 days
  3. গ) 12 days
  4. ঘ) 8 days
ব্যাখ্যা
Question: Some persons can do a piece of work in 24 days. Two times the number of such persons will do half of that work in -

Solution:
Let the initial workers be x
So, workers for 2nd time = 2x

x persons can complete 1 part in 24 days
1 person can complete 1 part in 24x days
2x persons can complete 1/2 part in 24x/(2x × 2) days
= 6 days
১১.
5 mat-weavers can weave 5 mats in 5 days. At the same rate, how many mats would be woven by 10 mat-weavers in 10 days?
  1. ক) 5 mats
  2. খ) 10 mats
  3. গ) 20 mats
  4. ঘ) 15 mats
ব্যাখ্যা
Question: 5 mat-weavers can weave 5 mats in 5 days. At the same rate, how many mats would be woven by 10 mat-weavers in 10 days?

Solution:
5 mat-weavers in 5 days can weave 5 mats
1 mat-weaver in 1 day can weave 5/(5 × 5) mats
10 mat-weavers in 10 days can weave (5 × 10 × 10)/(5 × 5) mats
= 20 mats
১২.
If a quarter kg of potato costs 20 Tk, how much Tk will 200 gm cost?
  1. ক) 12 Tk
  2. খ) 15 Tk
  3. গ) 16 Tk
  4. ঘ) 18 Tk
ব্যাখ্যা
Question: If a quarter kg of potato costs 20 Tk, how much Tk will 200 gm cost?

Solution:
A quarter of 1 kg = 1/4 kg
200 gram = 200/1000 = 1/5 kg

1/4 kg of potato's cost is 20 Tk
1 kg of potato's cost is 20 × 4 Tk
1/5 kg of potato's cost is (20 × 4)/5 Tk
= 16 Tk
১৩.
A and B together can complete a work in 12 days. A alone can complete it in 20 days. If B does the work only for half a day daily, then in how many days A and B together will complete the work?
  1. ক) 10 days
  2. খ) 15 days
  3. গ) 18 days
  4. ঘ) 22 days
ব্যাখ্যা
Question: A and B together can complete a work in 12 days. A alone can complete it in 20 days. If B does the work only for half a day daily, then in how many days A and B together will complete the work?

Solution:
B's 1 day's work = 1/12 - 1/20 = 1/30
If B does the work half a day, then he will do = 1/30 ÷ 2 = 1/60

Now, (A + B)'s 1 day's work = 1/20 + 1/60 = 1/15

So, A and B together will complete the work in 15 days.
১৪.
A takes twice as much as B or thrice as much time as C to finish a piece of work. Working together, they can finish the work in 3 days. A can do the work alone in -
  1. ক) 18 days
  2. খ) 12 days
  3. গ) 9 days
  4. ঘ) 6 days
ব্যাখ্যা
Question: A takes twice as much as B or thrice as much time as C to finish a piece of work. Working together, they can finish the work in 3 days. A can do the work alone in -

Solution:
Let, A, B, and C take 6x, 6x/2 = 3x, and 6x/3 = 2x respectively

Now, 
(1/6x) + (1/3x) + (1/2x) = 1/3
⇒ 6/6x = 1/3
⇒ 1/x = 1/3
⇒ x = 3

So, A takes = 6 × 3 = 18 days
১৫.
A, B, and C can complete a piece of work in 8, 12, and 24 days respectively. Working together, they will complete the same work in -
  1. ক) 6 days
  2. খ) 3 days
  3. গ) 8 days
  4. ঘ) 4 days
ব্যাখ্যা
Question: A, B, and C can complete a piece of work in 8, 12, and 24 days respectively. Working together, they will complete the same work in -

Solution:
(A + B + C)'s 1 days work = 1/8 + 1/12 + 1/24 
= (3 + 2 + 1)/24
= 6/24
= 1/4

A, B, and C together can complete the work in = 4 days
১৬.
A can do a certain job in 12 days. B is 60% more efficient than A. How many days does B alone take to do the same job?
  1. ক) 7.2 days
  2. খ) 8 days
  3. গ) 7.5 days
  4. ঘ) 9 days
ব্যাখ্যা
Question: A can do a certain job in 12 days. B is 60% more efficient than A. How many days does B alone take to do the same job?

Solution:
A completes one job in 12 days.
Hence the fraction of the job completed by A in 1 day =1/12

Since B is 60% more efficient than A,
Hence the fraction of the total job completed by B on one day =1/12 + 1/12 × (60/100)
= 1/12 + 1/20
= (5 + 3)/60
= 8/60
= 2/15

B can finish the job in 15/2 = 7.5 days
১৭.
A can do a piece of work in 24 days. When he had worked for 4 days, B joined him. If the work was finished in 16 days, B can alone finish that work is -
  1. ক) 20 days
  2. খ) 30 days
  3. গ) 36 days
  4. ঘ) 32 days
ব্যাখ্যা
Question: A can do a piece of work in 24 days. When he had worked for 4 days, B joined him. If the work was finished in 16 days, B can alone finish that work is -

Solution:
A's 1 day's work = 1/24 part
A's 16 day's work = 16/24 part
= 2/3 part

Remaining work  = 1 - 2/3 = 1/3 part

1/3 part work done by B in 16 - 4 = 12 days
1 part work done by B in 12 × 3 = 36 days
১৮.
A can do 1/4 of a work in 10 days, B can do 40% of the work in 40 days, and C can do 1/3 of the work in days. Who will complete the work first?
  1. ক) A
  2. খ) B
  3. গ) C
  4. ঘ) A and B
অনির্ধারিত
ব্যাখ্যা
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প্রশ্নটি হবে -
Question: A can do 1/4 of a work in 10 days, B can do 40% of the work in 40 days, and C can do 1/3 of the work in 13 days. Who will complete the work first?

Solution:
Whole work will be done by A in (10 × 4) = 40 days
Whole work will be done by B in (40 × 100/40) = 100 days
Whole work will be done by C in (13 × 3) = 39 days

সে অনুসারে সঠিক উত্তর হতো - গ) C
১৯.
5 men and 2 boys working together can do four times as much as work as a man and a boy. Working capacities of a man and a boy are in the ratio -
  1. ক) 1 : 2
  2. খ) 2 : 1
  3. গ) 1 : 3
  4. ঘ) 3 : 1
ব্যাখ্যা
Question: 5 men and 2 boys working together can do four times as much as work as a man and a boy. Working capacities of a man and a boy are in the ratio -

Solution:
Let, 1 man's 1 days's work = x
and 1 boy's 1 day's work = y

ATQ,
5x + 2y = 4(x + y)
⇒ 5x + 2y = 4x + 4y
⇒ x = 2y
⇒ x/y = 2/1
⇒ x : y = 2 : 1
২০.
In a camp, there is a meal for 120 men or 200 children. If 150 children have taken the meal, how many days men will be catered to with the remaining meal?
  1. ক) 20 men
  2. খ) 24 men
  3. গ) 30 men
  4. ঘ) 36 men
ব্যাখ্যা
Question: In a camp, there is a meal for 120 men or 200 children. If 150 children have taken the meal, how many days men will be catered to with the remaining meal?

Solution:
Camp has = 200 children
Already have taken meal  = 150 children

Remaining children to take meal = 200 - 150 = 50 children

the camp has meal for 200 children = 120 men
the camp has meal for 1 children = 120/200 men
the camp has meal for 50 children = (120 × 50)/200 men
= 30 men