a. A sum of money doubles itself in 4 years at a certain rate of interest. In how manyyears will it triple itself at the same rate of interest ? b. A sum of money trebles itself in 6 years at a certain rate of interest. In how many years will it become four times itself at the same rate of interest ?

a. A sum of money doubles itself in 4 years at a certain rate of inter

1.	a. A sum of money doubles itself in 4 years at a certain rate of interest. In how manyyears will it triple itself at the same rate of interest ? b. A sum of money trebles itself in 6 years at a certain rate of interest. In how many years will it become four times itself at the same rate of interest ?
Answer» ANSWER :a. 8 YEARS B. 9 years