Class 7 maths Unitary method and Profit and loss

The cost of 40 meters of cloth is Rs 200. Find the cost of 50 meters of cloth.

• RS 240

• RS 150

• RS 250

• RS 100

Answer explanation

Given cost of 40 meters of cloth = Rs 200

Cost of 1 meter of cloth = (200/40)

Therefore, the cost of 50 chocolates = (200/40) × 50

= Rs 250

Travelling 900 km by rail costs Rs 280. What would be the fare for a journey of 360 km when a person travels by the same class?

• RS 547

• RS 112

• RS 224

• RS 671

Answer explanation

Given that cost of travelling 900 km by rail = Rs 280

Therefore cost of travelling 1 km by rail = (280/900)

Hence, Cost of travelling 360 km by rail = (280/900) × 360

= Rs 112

If the sales tax on a purchase worth Rs 60 is Rs 4.20. What will be the sales tax on the purchase worth of Rs 150?

• RS 56.4

• RS 11.12

• RS 10.50

• RS 102.45

Answer explanation

Given sales tax on the purchase worth of Rs 60 = Rs 4.20

Sales tax on the purchase worth of Rs 1 = Rs 4.2060

Hence, sales tax on the purchase worth of Rs 150 = (4.20/60) × 150

= Rs 10.50

52 packets of 12 pencils each, cost Rs 499.20. Find the cost of 65 packets of 10 pencils each.

• RS 821

• RS 520

• RS 614

• RS 117

Answer explanation

Given total number of pencils in 52 packets of 12 pencils each = 52 × 12

= 624 pencils

Also, given that cost of 624 pencils = Rs 499.20

Cost of 1 pencil = (499.20/624)

Number of pencils in 65 packets of 10 pencils each = 65 x 10

= 650 pencils

Therefore, cost of 650 pencils = (499.20/624) × 650

= Rs 520.

Given the following values, find the unknown values:

(i) C.P. = Rs 1200, S.P. = Rs 1350 Profit/Loss?

• RS 217

• RS 114

• RS 542

• RS 150

Answer explanation

(i) Given CP = Rs. 1200, SP = Rs. 1350

Clearly CP < SP. So, profit.

Profit = SP – CP

= Rs. (1350 – 1200)

= Rs. 150

C.P. =? S.P. = Rs 1254, Loss = Rs 32

• RS 450.25

• RS 2395.50

• RS 2035.10

• RS 1050.24

Answer explanation

Given CP = ?, SP = Rs. 2390, loss = Rs. 5.50

Loss = CP – SP

5.50 = CP – 2390

= Rs. (5.50 + 2390)

= Rs. 2395.50

Calculate the profit or loss and profit or loss percent in each of the following cases:

(i) C.P. = Rs 4560, S.P. = Rs 5000

• 82.12%

• 66%

• 96.5%

• 14.96%

Answer explanation

(i) Given CP = Rs. 4560, SP = Rs. 5000

Here, clearly SP > CP. So, profit.

Profit = SP – CP

= Rs. (5000 – 4560)

= Rs. 440

Profit % = {(Profit/CP) x 100} %

= {(440/4560) x 100} %

= {0.0965 x 100} %

Profit % = 9.65%

Find the gain or loss percent, when:

(i) C.P. = Rs 2300, Overhead expenses = Rs 300 and gain = Rs 260.

• 13%

• 10%

• 25%

• 56%

Answer explanation

i) Given CP = Rs. 2300, overhead expenses = Rs. 300 and gain = Rs. 260

We know that Gain % = {(Gain/ (CP + overhead expenses)} x 100

= {260/ (2300 + 300} x 100

= {260/2600} x 100

Gain = 10%

A vendor buys oranges at Rs 26 per dozen and sells them at 5 for Rs 13. Find his gain percent.

• 59%

• 17%

• 20.3%

• 15.4%

Answer explanation

iven CP of 1 dozen oranges = Rs. 26

CP of 1 orange = 26/12

= Rs. 2.16

CP of 5 oranges = 2.16 x 5

= Rs. 10.8

Now, SP of 5 oranges = Rs. 13

Gain = SP – CP

= Rs. (13- 10.8)

= Rs. 2.2

Gain %= (Gain/CP) x 100

= (2.2/10.8) x 100

Gain = 20.3%

. A shopkeeper makes a profit of 15% by selling a book for Rs 230. What is the C.P. and the actual profit?

• RS 75

• RS 68

• RS 55

• RS 30

Answer explanation

Given that the SP of a book = Rs. 230

Profit % = 15

Since

CP = (SP x 100)/ (100 + profit %)

CP = (230x 100)/ (100 + 15)

CP = 23000/ 115 = Rs. 200

Also, Profit = SP – CP = Rs. (230 – 200) = Rs. 30

Actual profit = Rs. 30