CDS 2026 (I) Elementary Mathematics, question 90

Topic: Arithmetic (percentage, ratio, interest, time and work, speed)

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Passage · Q89 to Q90

A person borrows a sum of ₹16,00016,000 on simple interest at the beginning of a year. After 44 months, ₹24,00024,000 more is borrowed at a rate of interest double the previous one. At the end of the year, the total interest on both the loans is ₹48004800.

Q90

What is the ratio of the interest on the first loan to the interest on the second loan ?

  1. (a) 1:21:2Correct answer
  2. (b) 2:32:3
  3. (c) 3:43:4
  4. (d) 4:54:5

Solution.

Answer: (a) 1:21:2

  1. Simple interest is proportional to principal × rate × time.
  2. The ratio is [16000×r×1]:[24000×2r×(8/12)]=16000:32000=1:2\lbrack 16000 \times r \times 1\rbrack:\left\lbrack 24000 \times 2r \times (8/12) \right\rbrack = 16000:32000 = 1:2.
  3. The actual value of r is unnecessary.