The age of the universe is about `10^17` years whereas the mankind has existed for `10^9` years. For how many seconds would the man have existed if the age of universe were 1 day ?

Age of the universe is about 10^(10) years whereas the mankind has existed for 10^6 years. How many seconds would the man have existed if age of universe were one day.

A man is 42 years old and his son is 12 years old. In how many years will the age of the son be half the age of the man at that time?

In 10 years, A will be twice as old as B was 10 years ago. If at present A is 9 years older than B , then present age of B is :

In 10 years, A will be twice as old as B was 10 years ago. If at present A is 9 years older than B , then present age of B is :

In 10 years, A will be twice as old as B was 10 years ago. If at present A is 9 years older than B , then present age of B is :

Bratin is now 18 years old, whereas his cousin is 7 years old. After how many years will Bratin's age be 1.5 times that of his cousin?

There are 30 students in a class .The average age of the first 10 students is 12.5 years .The average age of the remaining 20 students is 13.1 years .What is the average age (in years ) of the students of the whole class ?