21.

The cost price of an article is 80% of its marked price for sale. How much per cent does the tradesman gain after allowing a discount of 12%?

• 20

• 12

• 10

• 10

A merchant has announced 25% rebate on prices of ready-made garments at the time of sale. If a purchaser needs to have a rebate of Rs. 400. then how many shirts, each costing Rs. 320, should he purchase?

• 10

• 7

• 6

• 6

A merchant purchases a wrist watch for Rs. 450 and fixes its list price in such a way that after allowing a discount of 10%, he earns a profit of 20%. Then the list price (in rupees) of the wrist watch is

• 500

• 600

• 750

• 750

A reduction of 10% in the price of tea enables of a dealer to purchase 25 kg more tea for Rs. 22500. What is the reduced price per kg of tea?

• Rs. 70

• Rs. 80

• Rs. 90

• Rs. 90

Ram donated 4% of his income to a charity and deposited 10% of the rest in a Bank. If now he has Rs. 8640 left with him, then his income is

• Rs. 12500

• Rs. 12,000

• Rs. 10,500

• Rs. 10,500

If the length of a rectangle is increased by 10% and its breadth is decreased by 10%, then its area

• decrease by 1%

• increases by 1%

• decreases by 2%

• decreases by 2%

Three spherical balls of radii 1 cm, 2 cm and 3 cm are melted to form a single spherical ball. In the process, the loss of material is 25%. The radius of the new ball is

• 6 cm

• 5 cm

• 3 cm

• 3 cm

If A : B = 2 : 3,  B : C = 4 : 5  and C : D = 5 : 9, then A : D is equal to

• 11 : 17

• 8 : 27

• 5 : 9

• 5 : 9

If the length of a rectangle is increased in the ratio 6 : 7 and its breadth is diminished in the ratio 5 : 4 then its area will be diminished in the ratio

• 17 : 16

• 15 : 14

• 9 : 8

• 9 : 8

7 years ago, the ages (in years) of A and B were in the ratio 4 : 5; and 7 years hence they will be in the ratio 5 : 6. The present age of B is

• 56 years

• 63 years

• 70 years

• 70 years