Maths question from Laboratory Attendant exam, 2026 by JKSSB
. If the difference between the compound interest and simple interest at 17% on a sum of money for 2 years (compounded annually) is Rs. 433.50, then the sum (in Rs.) is:
Last updated Jun 19, 2026
Correct Answer:
Option B —
15,000
To find the total sum of money, we can look at the basic difference between simple interest and compound interest over a two-year period.
Understanding the Difference
For the first year, both simple interest and compound interest are exactly the same.
In the second year, simple interest stays the same as the first year. However, compound interest charges interest on the principal amount plus interest on the interest earned during the first year.
Therefore, the entire difference between compound interest and simple interest after two years is simply the interest earned on the first year's interest.
Step-by-Step Calculation
1. Identify the relationship
The difference given is 433.50 rupees, and the interest rate is 17 percent. This means that 17 percent of the first year's interest is equal to 433.50 rupees.
2. Find the interest for the first year
To find the total interest for the first year, we divide 433.50 by 17 and then multiply by 100:
433.50 divided by 17 equals 25.50
25.50 multiplied by 100 equals 2550 rupees
So, the interest earned in the first year is 2550 rupees.
3. Find the original sum of money
Since the simple interest rate is 17 percent per year, the first year's interest (2550 rupees) is exactly 17 percent of the original total sum.
To find the original sum, we divide 2550 by 17 and then multiply by 100:
2550 divided by 17 equals 150
150 multiplied by 100 equals 15000 rupees
Correct Answer:
B) 15,000
Answer verified by Quintessence Classes faculty — Karan Nagar, Srinagar.
