how do i solve simple interest and compound interest

Hi,

Simple Interest is usually calculated using a simple

$$SI = \frac{P*R*T}{100} $$
SI = Simple Interest
P = Principal or amount borrowed or lent initially
R = Rate of Interest (per annum)
T = Time in years.

Principal earned at the rate of interest compounded annually after a certain period of time can be calculated by using a

A = P $$[1+\frac{R}{100}]^n$$
A = Amount due
P = Initial principal
R = Rate of Interest (in % p.a.)
n = Time (years)

Check out the cheatsheet for more tips and tricks: https://cracku.in/banking/quant/banking-interest/cheatsheet