Question

A sum of money becomes 8/5 of itself in 5 year at the certain rate of interest the rate per cent per Annam

Answer 1

Step-by-step explanation:

Let the Initial principle amount =P

After 5 years the amount received =(58)P

As the interest applicable is simple interest, the total interest is Final amount received − Initial principle amount.

Interest amount for 5 years =(58)P−P

Interest amount for 5 years =(53)P

With simple interest, interest amount every year is the same.

Thus interest for one year = Interest for 5 years ÷5

Interest for one year =5(53)P

Interest for one year =253P

Simple Rate of interest per year =Initial Principle amountAmount of Interest received per year ×100%

∴ Rate of interest per year =((253)P÷P)×100%

∴ simple rate of interest =253×100%

∴ Simple Rate of interest =12%