Multiple choice

What sum of money borrowed on $24^{th}$ May will amount to Rs.10,210.20 on $17^{th}$ October of the same year at 5 per cent per annum simple interest.

  1. Rs.$9,811$
  2. Rs$.10,010$
  3. Rs.$13,526$
  4. Rs.$15,530$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Time from May 24 to Oct 17: May (7 days) + June (30) + July (31) + Aug (31) + Sept (30) + Oct (17) = 146 days. 146 days = 146/365 years = 0.4 years. Amount = P(1 + RT/100) = P(1 + 5*0.4/100) = P(1 + 0.02) = 1.02P. 10210.20 = 1.02P => P = 10010.

AI explanation

Counting the days from 24th May to 17th October gives 7 days in May, 30 in June, 31 in July, 31 in August, 30 in September, and 17 in October, totaling 146 days. Using the simple interest formula, the amount is Principal plus (Principal times Rate times Time divided by 36500), so 10210.20 equals Principal times (1 plus (5 times 146 divided by 36500)). Simplifying the time fraction gives 0.02, meaning the amount is 1.02 times the Principal. Therefore, the principal is 10210.20 divided by 1.02, which is Rs. 10010.

Keep practicing — related questions