Correct Option (C)
The problem states that 18 instalments account for 60 percent of the total loan refunded. To determine the total number of instalments for 100 percent of the loan, a direct proportionality can be applied.
- If 60% of the loan corresponds to 18 instalments.
- Then, 1% of the loan corresponds to 6018 instalments.
- Therefore, 100% of the loan corresponds to 6018×100 instalments.
- Calculating this value: 6018×100=103×100=3×10=30 instalments.
Thus, there were 30 instalments in the agreement.
Incorrect Options:
Options A (22), B (24), and D (33) are incorrect as they do not satisfy the given condition that 18 instalments represent 60 percent of the loan. If any of these options were the total number of instalments, the percentage of the loan refunded after 18 instalments would be different:
- For 22 total instalments: 2218×100%≈81.8%
- For 24 total instalments: 2418×100%=75%
- For 33 total instalments: 3318×100%≈54.5%
None of these percentages match the given 60 percent, confirming that 30 is the only correct total number of instalments.