a lent rs . 5000 to b for 2 years and rs . 3000 to c for 4 years on simple interest at the same rate of interest and received rs . 2200 in all from both of them as interest . the rate of interest per annum is :
"explanation : let the rate of interest per annum be r % simple interest for rs . 5000 for 2 years at rate r % per annum + simple interest for rs . 3000 for 4 years at rate r % per annum = rs . 2200 ⇒ 5000 × r × 2 / 100 + 3000 × r × 4 / 100 = 2200 ⇒ 100 r + 120 r = 2200 ⇒ 220 r = 2200 ⇒ r = 10 i . e , rate = 10 % . answer : option b"
multiply(divide(2200, add(multiply(5000, 2), multiply(3000, 4))), const_100)