What is the rate of simple interest for the last 5 years if the sum of ₹480 becomes ₹792 in 11 years and the rate of interest for the first 6 years is 5%?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 7%
Given:
Principal $P=₹480$
Total Amount after 11 years $A=₹792$
So, total simple interest for 11 years:
$SI=792−480=₹312$
Interest for first 6 years at 5%
$SI_1 = \frac{480 \times 5 \times 6}{100} = ₹144$
Interest for last 5 years
$SI_2 = 312 - 144 = ₹168$
Rate of interest for last 5 years
$168 = \frac{480 \times R \times 5}{100}$
$R = \frac{168 \times 100}{480 \times 5} = 7\%$