If a person borrows money at a compound interest for 3 years, then calculate the amount to be returned in 3 years. I. After 5 years, Rs. 800 has to be paid as simple interest. II. The interest is rated at 5% per annum. III. The amount to be paid after 3 years as simple interest is equal to 6 times the amount when it was borrowed. Which statement(s) is/are required to answer the question?
If a person borrows money at a compound interest for 3 years, then calculate the amount to be returned in 3 years. I. After 5 years, Rs. 800 has to be paid as simple interest. II. The interest is rated at 5% per annum. III. The amount to be paid after 3 years as simple interest is equal to 6 times the amount when it was borrowed. Which statement(s) is/are required to answer the question? Correct Answer Statement I and either statement II or statement III together are sufficient to answer the question.
Considering statements I and II together
S.I. after 1 year will be 800/5 = Rs. 160
r = 5% and t = 1 year
⇒ P = 160 × 100/5 = 3200
∵ We have Rate, Time and Principal
Required amount can be calculated.
Both the statements I and II together are sufficient.
Considering statements II and III together
r = 5%
S.I. = 6P
∵ The principal can not be calculated
∴ Both II and III together are not sufficient to answer the question.
Considering statements I and III together
S.I. = 6P
⇒ PRT/100 = 6P
⇒ 3R/100 = 6
⇒ R = 200%
S.I. = PRT/100
800 = P × 200 × 5/100
P = 80
∵ We have Principal, Rate and Time
Required amount can be calculated.
∴ Both I and III together are also not sufficient to answer the question
⇒ Statement I and either statement II or statement III together are sufficient to answer the question.