উত্তর
ব্যাখ্যা
Solution:
CP = Tk. x
SP= (175/2)% of x
= (175/2) × (1/100) × x
= 7x/8
Required ratio = x : 7x/8
= 1 : 7/8
= 8 : 7
PrepBank · বিষয়ভিত্তিক প্রশ্ন
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Let,
the sum paid to Y per week be Tk. x
Then, sum paid to X per week
= 120% of Tk. x
= Tk. (120/100) × x
= Tk. (6/5) x.
∴ x + (6x/5) = 550
⇒ 11x/5 = 550
⇒ x = (550 × 5)/11
= Tk. 250.
Question: Kamrul bought a house, whose sale price was Tk. 8 lakh. He availed 20% discount as an early bird offer and then 10% discount due to cash payment. After that he spent 10% of the cost price in interior decoration and the lawn of the house. At what price should he sell the house to earn a profit of 25%?
Solution:
Here, original price = 8,00,000 Tk
After 20% early bird discount,
8,00,000 × (1 - 0.20) = 6,40,000 Tk
After 10% cash discount,
6,40,000 × (1 - 0.10) = 5,76,000 Tk
Renovation cost = 10% of 5,76,000
= (10/100) × 5,76,000
= 57,600 Tk
∴ Total CP = 5,76,000 + 57,600 = 6,33,600 Tk
Now,
Profit amount = 25% of 6,33,600
= (25/100) × 6,33,600
= 1,58,400 Tk
∴ Required SP = 6,33,600 + 1,58,400 = 7,92,000 Tk
30% ক্ষতিতে দাম, 70% = 6384
30% লাভে দাম, 130% = (6384 × 130)/70
= 11856
Question: A box contains 200 marbles, 25% of which are of black colour. Babu took some marbles from the box and found that 30% of them are black. Of the remaining marbles, 10% were black marbles. How many marbles did Babu take?
Solution:
বাক্সে মার্বেল আছে = 200 টি
কালো মার্বেল আছে = 200 এর 25%
= 200 এর 25/100
= 50 টি
ধরি
বাবু বাক্স হতে মার্বেল তুলে ছিলো x টি
প্রশ্নমতে
x এর 30% + (200 - x) এর 10% = 50
⇒ 30x/100 + 10(200 - x)/100 = 50
⇒ (30x + 2000 - 10x)/100 = 50
⇒ 20x + 2000 = 5000
⇒ 20x = 5000 - 2000
⇒ 20x= 3000
∴ x = 150
বাবু বাক্স হতে মার্বেল তুলে ছিলো 150 টি
ধরি,
19 টি জিনিসের ক্রয়মূল্য x টাকা
∴ 29 টি জিনিসের বিক্রয়মূল্য x টাকা
∴ ক্ষতি = (x/19) - (x/29)
= (29x - 19x)/551 = 10x/551 টাকা
∴ শতকরা ক্ষতির পরিমাণ = (10x/551)/(x/19) × 100%
= (10x/551) × (19/x) × 100%
= 34.48%
Question: A tradesman fixed his selling price of goods at 25% above the cost price. He sells half the stock at this price, one-quarter of his stock at a discount of 20% on the original selling price, and the rest at a discount of 40% on the original selling price. Find the gain percentage altogether?
Solution:
Let C.P = 100;
then S.P = 100 + 25 = 125 Tk
Now, revenue
= [(1/2) × 125] + [(1/4) × (80/100) × 125] + [(1/4) × (60/100) × 125]
= 62.5 + 25 + 18.75
= 106.25
∴ Gain = 106.25 - 100
= 6.25 Tk
Gain percentage = (6.25 × 100)/100
= 6.25%
Question: After selling a saree for Tk. 3360 a shopkeeper suffers a loss of 16%. If he wants to earn 15% profit after giving the discount of 8%, what will be the marked price of the saree?
Solution:
At 16% loss,
Selling price Tk. 84 when cost price Tk. 100
Selling price Tk. 1 when cost price Tk. 100/84
Selling price Tk. 3360 when cost price Tk. (100 × 3360)/84
= Tk. 4000
At 15% profit,
cost price Tk. 100 when selling price Tk. 115
cost price Tk. 1 when selling price Tk. 115/100
cost price Tk. 4000 when selling price Tk. (115 × 4000)/100
= Tk. 4600
At 8% discount,
Selling price Tk. 92 when marked price Tk. 100
Selling price Tk. 1 when marked price Tk. 100/92
Selling price Tk. 4600 when marked price Tk. (100 × 4600)/92
= Tk. 5000
∴ The marked price of the saree should be Tk. 5000.
Let the Cost price of the Chair be y taka.
Selling price = y - 25% of y
= y - 25y/100
= 75y/100
= 3y/4
Therefore 3y/4 = 930
or, y = 1240
So, To gain 25%, Selling Price would be
= 1240 + 25% of 1280
= 1240 + 310
= 1550
= 1600 taka
Team won 40 games out of 60 and the remaining games were 30.
Total games = 60 + 30
= 90
70% of 90 = 63
Team has to win 63 games in total.
Team has already won 40.
∴ Games to win = 63 - 40
= 23
Question: Arif bought a ticket of a cricket match for Tk. 25 and later sold the ticket to Rafi for Tk. 75. What was the percent increase in the price of the ticket?
Solution:
ক্রয়মূল্য = 25 টাকা
বিক্রয়মূল্য = 75 টাকা
লাভ = 75 - 25 = 50 টাকা
25 টাকায় লাভ হয় = 50 টাকা
1 টাকায় লাভ হয় = 50 / 25 টাকা
100 টাকায় লাভ হয় = (50 × 100)/25 টাকা = 200 টাকা
শতকরা লাভ 200%
Question: What is the minimum percentage increase in the mean of set X {-4, -1, 0, 6, 9} if its two smallest elements are replaced with two different primes?
Solution:
old mean = - 4 - 1 + 6 + 9 /5 = 2
-4, -1 will be replaced by 2, 3
new mean = 2 + 3 + 6 + 9 /5 = 4
%increase = {(4 - 2)/2} × 100%
= 100%
Given loss = 10% profit = 10%
Difference of overall profit and loss = 10 - (-10) = 20%
20% of cp = sp
20/ 100×cp = 108
20 × cp = 108 × 100
cp = 10800/20
∴ cp = 540
Question: If Adnan’s salary is 60% higher than Bina’s salary, by what percentage is Bina’s salary less than Adnan’s?
Solution:
Let,
Bina’s Salary is Tk. 100.
Then,
∴ Adnan’s Salary = (100 + 60% of 100)
= 100 + (60× 100)/100
= 100 + 60
= 160
∴ Difference between Adnan’s Salary and Bina’s Salary = 160 - 100 = 60
∴ lower = (60/160) × 100 = 37.5%
∴ Bina’s salary is 37.5% lower than Adnan’s salary.
Quantity of alcohol in vessel P = 62.5/100 × 2 = 5/4 litres
Quantity of alcohol in vessel Q = 87.5/100 × 4 = 7/2 litres
Quantity of alcohol in the mixture formed = 5/4 + 7/2 = 19/4 = 4.75 litres
As 6 litres of mixture is formed, ratio of alcohol and water in the mixture formed
= 4.75 : 1.25 = 19 : 5.
Question: The price of a phone is Tk. 8000. Its price is first increased by 25% and then decreased by 20%. What is the present price of the phone?
Solution:
Initial Cost = Tk. 8000
After 25% increase in the cost, it becomes,
(8000 + 25% of 8000)
= 8000 + 2000
= Tk. 10000
Now, cost is decreased by 20%, so cost will become,
(10000 - 20% of 10000)
= 10000 - 2000
= Tk. 8000
So, present cost is Tk. 8000.
Cost price of one doughnut = 35/100 = 0.35
Selling price of one doughnuts = 7.20/12 = 0.6 tk
Profit in one doughnuts = 0.6 - 0.35 = 0.25 tk
So, Total doughnuts bought = 30 / 0.25 = 120
x + y + xy/100
= 10 - 10 - (100/100)
= -1%
so, 1% = 10
and 100% = 10 × 100
= 1000
Question: A candidate has to obtain a minimum of 40% of the total marks to pass. He got 30% of the total marks and failed by 50 marks. What are the maximum marks?
Solution:
Let the maximum marks be x.
Then,
40% of x - 30% of x = 50
⇒ 10% of x = 50
⇒ 10x/100 = 50
⇒ x= (50 × 100)/10
∴ x = 500
Question: The bus fare was recently raised from Tk. 3.70 to Tk. 4.00 per kilometer. What is the approximate percentage increase?
Solution:
বাস ভাড়া বাড়ে = (4.00 - 3.70) টাকা
= 0.30 টাকা
বাস ভাড়া শতকরা বাড়ে = (0.30/3.70) × 100%
= 8.1 %
≈ 8%
Question: A toaster machine is priced at Tk. 25,000 and sold with two successive discounts of 15% and 10%. What is its final selling price?
Solution:
Given,
Marked Price = Tk. 25000
Price after 15% discount
= 25000 - (15% of 25000)
= 25000 - 3750
= Tk. 21,250
Price after 10% discount
= 21250 - (10% of 21250)
= 21250 - 2125
= Tk. 19,125
∴ Final Selling Price = Tk. 19,125
Question: A shirt with a list price of Tk. 150 is sold for Tk. 105 after two successive discounts. If the second discount is 12.5%, what was the rate of the first discount?
Solution:
Let the first discount be x%.
∴ After the first discount,
∴ the price = (100 − x)% of 150
= (100 − x)/100 × 150
After the second discount of 12.5%,
the selling price = 87.5% of the first discounted price
= 87.5/100 × (100 − x)/100 × 150
Given selling price = 105,
ATQ,
87.5/100 × (100 − x)/100 × 150 = 105
⇒ 100 − x = (105 × 100 × 100) / (87.5 × 150)
⇒ 100 − x = 80
∴ x = 100 − 80
= 20
∴ The first discount is 20%.
আমরা অপশন গুলো বিবেচনা করি -
A. 1/25 = 1/25 × 100% = 4%
B. 4/100 = 1/25 = 4%
C. .04 = 4/100 = 40/100 × 100% = 40%
D. 0.04 = 4/100 = 1/25 = 4%
সুতরাং, অপশন গ) 40% সঠিক উত্তর।
ধরি,
দ্রব্যটির ক্রয়মূল্য 100 টাকা
25% লাভে দ্রব্যটির বিক্রয়মূল্য = 100 + 25 = 125 টাকা
অর্থাৎ দ্রব্যটি দামের 80% হলো = 125 টাকা
∴ দ্রব্যটি দামের 100% হলো = (125 × 100)/80
= 156.25 টাকা
∴ শতকরা লাভ হতো = 156.25 - 100 = 56.25%
Question: A shopkeeper buys a mobile phone for Tk. 8,000 and sells it to a retailer at a profit of 15%. The retailer then sells it to a customer at a profit of 10%. How much does the customer pay for the mobile phone?
Solution:
দোকানদারের 15% লাভে বিক্রয়মূল্য = 8000 + 8000 এর 15%
= 8000 + (8000 × 15 / 100)
= 8000 + 1200
= Tk. 9200
দোকানদারের বিক্রয়মূল্য = খুচরা বিক্রেতার ক্রয়মূল্য
খুচরা বিক্রেতার 10% লাভে বিক্রয়মূল্য = 9200 + 9200 এর 10%
= 9200 + (9200 × 10 / 100)
= 9200 + 920
= Tk. 10120
সুতরাং, খুচরা বিক্রেতার বিক্রয়মূল্য = ক্রেতার ক্রয়মূল্য = Tk. 10,120
Winner gets 65% 0f valid votes and loser gets 35% of votes.
Difference between this two = 2748
(65-35)% = 2748
30% = 2748
Total number of voters, 100%
= (2748×100)/30
= 9160
Let the cost price = 100 units
Marked price = 120 units
Selling price = 120 × 80/100 = 96 units
There will be loss
Loss% = 100−96 /100 × 100 = 4%
Let, Marked price = Tk. x
∴x× 70/100 × 85/100 =476
⇒ x = 476 × 100/70 ×100/85
⇒ x= Tk. 800
Let, A's profit = 42,360 = 5x
So, x = 42,360/5 = 8472
total profit = 5x + 7x + 8x = 20x = 20×8472
∴ The total profit is tk. 1,69,440
If the population increases by 50% then you're multiplying the previous number by 3/2. So to work backwards, divide by 3/2 (which is the same as multiplying by 2/3).
So we have:
1950: 810
1900: 810×(2/3) = 540
1850: 540×(2/3) = 360
1800: 360×(2/3) = 240
1750: 240×(2/3) = 160
Required money = Present Worth of Tk. 10028 due 9 months hence
= Tk. [{10028 × 100}/{100 +(12 × 9/12)}]
= Tk. 9200
Questjion: A man buys an article for 20% less than its value and sells it for 20% more than its value. What is his gain or loss percentage?
Solution:
Let, the value of article is x Tk.
Buying price at 20% less,
= x - 20% of x
= x - (20x/100)
= x - 0.2x
= 0.8x Tk.
Selling Price at 20% more,
= x + 20% of x
= x + 0.2x
= 1.2x Tk.
Profit = 1.2x - 0.8x
= 0.4x Tk.
∴ Profit Percentage = (0.4x/0.8x) × 100%
= (40/0.8)%
= 50%
∴ The gain percentage is 50%.
Question: The population of a town increases by 10% in the first year and decreases by 10% in the next year. What is the overall percentage change?
Solution:
Let the initial population = 100
Population after 1st year (10% increase)
Population = 100 + 10% of 100 = 100 + 10 = 110
Population after 2nd year (10% decrease)
Population = 110 - 10% of 110 = 110 - 11 = 99
Overall change = Final population - Initial population
= 99 - 100
= - 1
Overall percentage change = (- 1/100) × 100% = - 1%
∴ Population decreased by 1%
Question: What percentage of the whole week does Sagor spend in school except lunch time, if his school times are 8 am to 4 pm from Monday to Saturday, with 2 hours for lunch each day?
Solution:
Time spent by Sagor in a day = 4 pm - 8 am = 8 hours
Except lunch time, Sagor spends in a day = 8 - 2 = 6 hours
Number of school days in a week = 6
Total school hours in a week = 6 × 6 = 36 hours
Total hours in a week = 7 × 24 = 168 hours
Percentage time spent in a week = (36/168) × 100%
= 21%
3% sugar solution = 50×(3/100) = 1.5 Liters of sugar
This amount must be 5% of a reduced final amount (50 - x)
ATQ,
1.5 = 5% × (50-x)
⇒ 50 - x = 150/5 = 30
∴ x = 20
Question: A bicycle is purchased for Tk. 200 and sold at a 10% loss. Find the selling price and the total loss incurred.
Solution:
Cost Price of the bicycle = Taka 200
Loss Percentage = 10%
∴ Loss Amount = Loss Percentage × Cost Price
= 10% × Taka 200
= Taka 20
∴ Selling Price = Cost Price - Loss Amount
= Taka 200 - Taka 20
= Taka 180
Total Loss Incurred: Tk. 20