DRDO Multi tasking staff Model paper 6

Let the rate be ‘R’.
Equation for final amount after adding compound interest is:
A = P × (1 + (R/100))‌n where P is Principal Amount, R is the rate of interest and n is the time span
⇒23328=20000× (1 + (R/100))‌2
⇒ 1.1664 = (1 + (R/100))‌2
Taking square root
⇒ 1.08 = 1 + (R/100)
⇒ 0.08 = R/100
⇒ R = 0.08 × 100 = 8%