A goldsmith observes that one of his employees prepares a necklace in 9 hours, while another employee prepares it in 10 hours. If they work together, they stud 10 gems less every hour and thus prepare a necklace in 5 hours, then the number of gems studded in each necklace is: 

The length of the two sides forming the right angle of a right-angled triangle are 6 cm and 8 cm, then find the length of its circum radius:

The average salary per head of all the workers of JK Campus is ₹ 60. The average salary of 12 center heads is ₹ 400 and of the rest is ₹ 56. The total number of workers in JK Campus is 

The present age of father and son are in the ratio 3: 1. After 20 years the ratio becomes 2 : 1 . Find the present age of the father. 

The present age of A and B are in the ratio 5: 4. After 10 years the ratio becomes 7: 6. Find the present age of A.

The sum of the squares of three numbers is 532 and the ratio of the second and also of the second to the third is 3 : 2 . What is the second number?

Aryan invested ₹ 5200 at 4 %, 6 % and 8 % per annum simple interest. At the end of the year, he got the same interest in all the three cases, find the money invested at 4%. 

A certain sum increases by 50 % in 5 years. Three sums x, y and z are lent for 10, 15 and 20 years respectively. If amount on each sum is equal, then find the ratio of x, y and z.