The following table gives the cost of different number of exercise books:
`
x(Number of exercise
book)
2 4 6 8 10 12 15
y(cost in Rs.) 20 40 60 80 100 120 150
Answers
Answer:
x(Number of exercise
book)
2 4 6 8 10 12 15
y(cost in Rs.) 20 40 60 80 100 120 150
Exercise 13.3 Solutions
Access answers to Maths RD Sharma Solutions For Class 8 Exercise 13.1 Chapter 13 Profit, Loss, Discount and Value Added Tax (VAT)
1. A student buys a pen for Rs 90 and sells it for Rs 100. Find his gain and gain percent.
Solution:
We know that the cost price of pen = Rs 90
Selling price of pen = Rs 100
By using the formula,
Gain = selling price – cost price
= 100 – 90
= Rs 10
By using the formula,
Gain % = (gain/cost price) × 100
= (10/90) × 100
= 100/9
= 11 1/9 %
2. Rekha bought a saree for Rs 1240 and sold it for Rs 1147. Find her loss and loss percent.
Solution:
We know that the cost price of saree = Rs 1240
Selling price of saree = Rs 1147
By using the formula,
Loss = cost price – selling price
= 1240 – 1147
= Rs 93
By using the formula,
Loss % = (loss/cost price) × 100
= (93/1240) × 100
= 7.5 %
3. A boy buys 9 apples for Rs 9.60 and sells them at 11 for Rs 12. Find his gain or loss percent.
Solution:
We know that the cost price of 9 apples = Rs 9.60
Cost price of 1 apple = Rs 9.60/9
Selling price of 11 apple = Rs 12
Selling price of 1 apple = Rs 12/11
By using the formula,
Gain = selling price – cost price
= 12/11 – 9.60/9
= (108-105.60)/99
= Rs 2.40/99
By using the formula,
Gain % = (gain/cost price) × 100
= ((2.40/99)/(9.60/9)) × 100
= 25/11
= 2 3/11%
4. The cost price of 10 articles is equal to the selling price of 9 articles. Find the profit percent.
Solution:
We know that the cost price of 10 article = selling price of 9 article
Let us consider CP of 1 article as Rs X
Selling price of 9 article = 10X
Selling price of 1 article = 10x/9
Profit = 10x/9 – x
= x/9
Profit % = Gain % = (gain/cost price) × 100
= (x/9)/x × 100
= 100/9
= 11 1/9%
5. A retailer buys a radio for Rs 225. His overhead expenses are Rs 15. If he sells the radio for Rs 300, determine his profit percent.
Solution:
The cost price of a radio = Rs 225
Overhead expenses = Rs 15
Total cost = cost price + overhead expenses = 225+15 = Rs 240
Selling price of radio = Rs.300
By using the formula,
Gain = selling price – cost price
= 300 – 240 = Rs 60
By using the formula,
Gain % = (gain/cost price) × 100
= 60/240 × 100
= 25 %
6. A retailer buys a cooler for Rs 1200 and overhead expenses on it are Rs 40. If he sells the cooler for Rs 1550, determine his profit percent.
Solution:
We know the cost price of cooler = Rs 1200
Overhead expenses = Rs 40
Total cost = Rs 1200 + Rs 40 = Rs 1240
Selling price of cooler = Rs 1550
By using the formula,
Gain = selling price – cost price
= Rs 1550 – Rs1240
= Rs 310
By using the formula,
Gain % = (gain/cost price) × 100
= 310/1240 × 100
= 25%
7. A dealer buys a wristwatch for Rs 225 and spends Rs 15 on its repairs. If he sells the same for Rs 300, find his profit percent.
Solution:
We know the cost price of wrist watch = Rs 225
Cost of repairing = Rs 15
Total cost = Rs 225 + Rs 15 = Rs 240
Selling price of watch = Rs 300
By using the formula,
Gain = selling price – cost price
= Rs 300 – Rs 240
= Rs 60
By using the formula,
Gain % = (gain/cost price) × 100
= 60/240 × 100
= 25%
8. Ramesh bought two boxes for Rs 1300. He sold one box at a profit of 20% and the other box at a loss of 12%. If the selling price of both boxes is the same, find the cost price of each box.
Solution:
We know the cost price of two boxes = Rs 1300
So let us consider cost price of one box be Rs x
Cost price of other box = Rs 1300 – x
Selling price of first box = x + x × 20/100
= x + x/5
= Rs 6x/5
Selling price of second box = (1300 – x) – (1300 – x) × 12/100
= Rs (28600 – 22x)/25
By equating SP of first and second box we get,
6x/5 = (28600 – 22x)/25
150x = 28600 × 5 – 110x
150x + 110x = 28600 × 5
260x = 28600 × 5
x = (28600 × 5)/260
= 550
∴ Cost price of first box = Rs. 550
Cost price of second box = Rs1300 – Rs550 = Rs 750
9. If the selling price of 10 pens is equal to cost price of 14 pens, find the gain percent.
Solution:
Given that, Selling price of 10 pens = cost price of 14 pens
So, let the cost price of 1 pen be Rs x
Selling price of 10 pens = Rs 14x
Selling price of 1 pen =Rs 14x/10
By using the formula,
Gain = selling price – cost price
= 14x/10 – x
= 4x/10
By using the formula,
Gain % = (gain/cost price) × 100
= (4x/10)/x × 100
= 2/5 × 100
= 40%
x = 576/192
We know that SP of 1 pen = 192x/200
SP of dozen pens = 12 × 192x/200
= 12 × 192/200 × 576/192
= 12 × 576/200
= 34.56
∴ Loss% = 4% and SP of 1 dozen pens is Rs 34.56
23. The difference between two selling prices of a shirt at profits of 4% and 5% is Rs 6. Find
(i) C.P. of the shirt
(ii) The two selling prices of the shirt
Solution:
(i) Let the CP of shirt be = Rs x
Profit (4%) = 4/100 of CP
= 4/100 × x
= 4x/100
Selling Price = C.P + Profit
= x + 4x/100
= (100x + 4x)/100
= 104x/100
(
Selling Price of other shirt = 105x/100 = (105×600)/100 = Rs 630
24. Toshiba bought 100 hens for Rs 8000 and sold 20 of these at a gain of 5%. At what gain percent she must sell the remaining hens so as to gain 20% on the whole?