131.

A man rows down a river 15 km in 3 h with the stream and returns in  The rate at which he rows in still water is

• 2.5 km/h

• 1.5 km/h

• 3.5 km/h

• 4.5 km/h

There is 100% increase to an amount in 8 yr, at simple interest. Find the compound interest of ₹ 8000 after 2 yr at the same rate of interest.

• ₹ 2500

• ₹ 2000

• ₹ 2250

• ₹ 2125

If the number p is 5 more than q and the sum of the squares of p and q is 55, then the product of p and q is

• 10

• -10

• 15

• -15

If  then the value of

• 0

• 2

• -2

• 4

If a + b + c = 2s, then
     is equal to

• a² + b² + c²

• 0

• 1

• 2

If (x + y) = 1,  then the value of 
                   is

• 3

• -3

• 1

• -1

If a³ - b³ - c³ = 0,  then the value of a⁹ - b⁹ - c⁹ - 3a³b³c³ is

• 1

• 2

• 0

• -1

A horse is tied to a post by a rope. If the horse moves along a circular path always keeping the rope stretched and describes 88 m when it has traced out 72° at the centre at the length of the rope is 

• 70 m

• 75 m

• 80 m

• 65 m

Maximum value of (2 sin θ + 3 cos θ) is

• 2

• 

• 

• 1

The value of 152 (sin 30° + 2 cos² 45° + 3 sin 30° + 4 cos² 45° +...+17 sin 30° + 18 cos² 45°) is

• an integer but not a perfect square

• a rational number but not an integer

• a perfect square of an integer

• irrational