Question

Jackie invested ₹12000 in a bank at 15% p.a., C.I. He pays 40% of his income from interest to a charitable trust every year. How much money does Jackie have after 4 years? 

पर्याय

• ₹16583.16

• ₹15683.6

• ₹16843

• None of these

Answer 1

None of these

Explanation:

Method-1:

Finally Jackie is earning interest at the rate of 9% p.a. only  

[∵ 15% − 40% of 15% = 15% − 6% = 9%]

Amount

= `12000 (1 + 9/100)^4`

= 12000 × (1.09)⁴

= 12000 × 1.411

= ₹16938.6

Method-2:

C.I. at end of 1 year = (12000 × 1.15) − 12000

12000 (0.15) = 1800

Amount for charity

= `40/100 xx 1800`

= 720

Amount for 2nd year = 12000+ (1800  − 720) = 13080

C.I. for 2nd year = 13080 (1.15) − 13080 = 1962

Amount for charity = 784.8 i.e. 40% of 1962.

Amount for 3rd year = 13080 + (1962 − 784.8)

= 14257.2

C.I. for 3rd year = 14257.2 (0.15) = 2138.58

Amount for charity = 855.432

Amount for 4th year = 14257.2 + (2138.58 − 855.432)

= 15540

C.I. for 4th year = 2331

Amount for charity = 932.4

Amount at end of 4th year

= 15540 + 2331 − 932.4

= 16938.6