81.

If the radius of a sphere is increased by 2m, its surface area is increased by 704 m². What is the radius of the original sphere?

• 16 m

• 15 m

• 14 m

• 14 m

A right circular cylinder is circumscribing a hemisphere such that their bases are common. The ratio of their volumes is

• 1 : 3

• 1 : 2

• 2 : 3

• 2 : 3

A man invested  of his capital at 7%,  at 8% and the remaining at 10% rate of simple interest. If his annual income from interests is Rs. 561, the capital invested was

• Rs. 6000

• Rs. 5600

• Rs. 6600

• Rs. 6600

The compound interest on Rs. 6250 at 12% per annum for 1 year, compound half-yearly is

• Rs 772.50

• Rs. 772

• Rs. 672.50

• Rs. 672.50

A sum of money lent at compound interest amounts to Rs. 1460 in 2 years and to Rs. 1606 in 3 years. The rate of interest per annum is

• 12%

• 11%

• 10.5%

• 10.5%

If A travels to his school from his house at the speed of 3 km/hr, then he reaches the school 5 minutes late. If he travels at the speed of 4 km/hr, he reaches the school 5 minutes earlier than school time. The distance of his school from his house is

• 1 km

• 2 km

• 3 km

• 3 km

A train travelling with a speed of 60 km/hr catches another train travelling in the same direction and then leaves it 120 m behind in 18 seconds. The speed of the second train is

• 26 km/hr

• 35 km/hr

• 36 km/hr

• 36 km/hr

A and B together can complete a piece of work in 12 days and B and C together in 15 days. If A is twice as good a workman as C, then in how many days will B alone complete the same work?

• 30

• 25

• 24

• 24

4 men and 6 women together can complete a work in 8 days while 3 men and 7 women together can complete it in 10 days. 20 women working together will complete it in

• 36 days

• 32 days

• 24 days

• 24 days

The average of two numbers A and B is 20, that of B and C is 19 and of C and A it is 21. What is the value of A?

• 24

• 22

• 20

• 20