A sum of money at simple interest amounts to Rs. 815 in 3 years and to Rs. 854 in 4 years. The sum is:
Aptitude
Simple Interest
Difficulty: Easy
Choose an option
Answer
Correct Answer: Rs. 698
Explanation
Given
- Amount after 3 years = Rs. 815
- Amount after 4 years = Rs. 854
Idea: In simple interest the interest per year is constant. The increase from year 3 to year 4 equals the interest of one year.
1 year's interest = 854 − 815 = 39Interest in 3 years = 3 × 39 = 117Principal P = Amount after 3 years − interest for 3 yearsP = 815 − 117 = Rs. 698
CheckInterest in 4 years = 4 × 39 = 156; P = 854 − 156 = 698 ✓