A sum of ₹y amounts to ₹10,920 at 6% per annum in a time in which a sum of ₹12,000 amounts to ₹15,000 at 5% per annum, both at simple interest. The value of y is:
Show answer & explanation
Correct answer: B
Explanation
Given:
₹y becomes ₹10,920 at 6% annual simple interest.
₹12,000 becomes ₹15,000 at 5% annual simple interest.
By the formula:
A = P(1 + RT/100)
From the second case:
15,000 = 12,000(1 + 5T/100)
15,000 / 12,000 = 1 + 5T/100
1.25 = 1 + 5T/100
0.25 = 5T/100
T = 5 years
Now in the first case:
10920 = y(1 + 6 × 5/100)
10920 = y(1 + 30/100)
10920 = y × 1.30
y = 10920 / 1.30
y = 8400