Question

if the sum of Rs.2,000 becomes Rs. 2,205 @ 5% per annum compound interest, then find the time​

Answer 1

Step-by-step explanation:

P=Rs.2000

R=5%

A=Rs.2205

A=P(1+100R)n

⇒2205=2000(1+1005)n

⇒20002205=(100105)n

⇒400441=(2021)n

⇒(2021)2=(2021)n

∵ Powers are equal if bases are equal n=2 i.e., Time =2 years

Answer 2

Step-by-step explanation:

• Interest amount is 2205-2000= 205
• Let's take 5% interest rate for 2 years, effective percentage will be, a+b+ab/100 [A, B are rate of interest]
• 5+5+25/100
• 10.25%
• Confirm it, 10.25% of 2000= 205...perfect
• 2 years is the answer