A sum of money at simple interest amounts to Rs 720 after 2 years and to Rs…
2023
A sum of money at simple interest amounts to Rs 720 after 2 years and to Rs 1020 after a further period of 5 years . The sum is
- A.
520
- B.
600
- C.
620
- D.
700
Attempted by 6 students.
Show answer & explanation
Correct answer: B
Key idea: the difference between the two amounts gives the simple interest for the intervening years.
Amount after 2 years = Rs 720; amount after 7 years = Rs 1020.
Simple interest for the 5 years between these dates = 1020 − 720 = Rs 300, so interest per year = 300 ÷ 5 = Rs 60.
Interest for 2 years = 2 × 60 = Rs 120.
Principal = amount after 2 years − interest for 2 years = 720 − 120 = Rs 600.
Answer: The sum is Rs 600.