The average salary per head of all workers of an institution is 60. The average salary per head of 12 officers is 400. The average salary per head of the rest is 56. Then the total number of workers in the institution is

(1 - 1/3)(1 - 1/4)(1 - 1/5)...(1 - 1/25) is equal to

Evaluate √(0.289/0.00121) + √(64/16)

The HCF and LCM of two numbers m and n are 6 and 210 respectively. If m + n = 72, then 1/m + 1/n is equal to

In ΔABC, ∠A = 90°, M is the mid-point of BC and D is a point on BC such that AD ⊥ BC. If AB = 7 cm and AC = 24 cm, then AD : AM is equal to

Richa travels from A to B at a speed of 15 km/h, from B to C at 20 km/h and from C to D at 30 km/h. If AB = BC = CD, find Richa's average speed.

A, B and C started a business by investing ₹13750, ₹16250 and ₹18750 respectively. If B's share in the profit earned by them is ₹5200, what is the total profit (in ₹) earned by them together?

The diagonal of a rectangle is 15 cm and its length is 12 cm. Find the area of the rectangle.

The ratio of alcohol and water in a mixture of 85 L is 11 : 6. How much water should be added to make the ratio 5 : 3?