With which sport is Yuki Bhanwari related?

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. 

Vivek is 30% more efficient than Neha. How much time will they, working together, take to complete a job which Vivek alone could have done in 23 days?

The marked price of a Robot is ₹ 18000. By selling it at a discount of 20%, the loss is 4%. Find the cost price of the Robot.