Shortcut trick
Let the Principle be 100.
P = 100, then A = 200 and SI will be 200 - 100 = 100
YES = 100 in 10 years
Rate = 100/10 = 10%.
∴ The interest rate is 10%.
The traditional method is:
Given:
Time period = 10 years
Formula used:
SI = (P × R × T)/100
A = P + SI
Where P = main amount, R = rate, T = time, SI = primary interest
Calculations:
Monetary amount 2P
YES = 2P - P
⇒ P = (P × R × 10)/100
⇒ 1 = R/10
⇒ R = 10%
∴ The interest rate is 10%