Paper 1 · Mathematical Reasoning and Aptitude
UGC NET June 2023 (13.06.2023) Shift-II
A sum of money doubles in 14 years. In how many years would it triple if the rate of interest is considered as simple?
A25 years
B28 years ✓ Correct
C18 years
D23 years
Correct answer: (B) 28 years — The sum triples in 28 years, so the answer is 28 years.
Explanation
★The sum triples in 28 years, so the answer is 28 years.
★Under simple interest the interest earned each year is constant.
★Doubling means the interest equals the principal, earned over 14 years.
★So the yearly interest is one-fourteenth of the principal.
★Tripling means the interest must equal twice the principal.
★At the same yearly rate, twice the principal takes twice the time, which is 28 years.
★This proportional shortcut works only for simple interest, where interest grows linearly with time.
Want more like this? Create a free account to practise a full test, track your progress, and get spaced-repetition review.
Shared by Mcqkart · via Mcqkart.in