The average age of three boys is 25 years and their ages are in the proportion 3 : 5 : 7. The age of the youngest boy is `9\ y e a r s` b. `15\ y e a r s` c. `18\ y e a r s` d. `21\ y e a r s`

The average age of three boys is 25 years and their ages are in the ratio 3:5:7 . The age of the youngest boy is :

The average age of three boys is 16 years. If their ages are in the ratio 4:5:7, then the age of youngest boy is

The average age of three boys is 15yr . If the ratio of their ages is 3:5:7 , what is the age of the oldest boy ?

The average age of r boys in a class is a years. If the average age of s of them is b years, them what is the average age of the remaining boys ?

Given that carbon-14 decays at a constant rate in such a way that it reduces to 50% in 5568 years, find the age of an old wooden piece in which the carbon is only 12.5% of the original. 15836 y e a r s b. 16668 y e a r s c. 16704 y e a r s d. 17552 y e a r s

The average age of seven boys sitting in a row facing North is 26 years. If the average age of the first three boys is 19 years and the average age of the last three boys is 32 years, what is the age of the boy who is sitting in the middle of the row? (a) 24 years (b) 28 years (c) 29 years (d) 31 years (e) None of these

The average age of the boys in a class is 16 years and that of the girls is 15 years.The average age for the whole class is (a) 15 years (b) 15.5 years ( c) 16 years (d) Cannot be computed with the given information

The value of a flat worth Rs. 500000 is depreciating, at the rate of 10% p.a. In how many years will it' value be reduced to Rs. 364500? 3\ y e a r s b. 4\ y e a r s c. 5\ y e a r s d. 6\ y e a r s