Question

Separately, Jack and Sristi invested the same amount of money in the stock market. Jack’s invested amount kept getting reduced by 50% every month. Sristi's investment is also reduced every month, but in an arithmetic progression with a common difference of Rs. 15000. They both withdrew their respective amounts at the end of the sixth month. They observed that if they had withdrawn their respective amounts at the end of the fourth month, the ratio of their amounts would have been the same as the ratio after the sixth month. What amount of money was invested by Jack in the stock market?

• A. Rs. 100000
• B. Rs. 120000
• C. Rs. 150000
• D. Rs. 180000
• E. None of the above

Answer 1

Answer: (A)

Rs. 100000

Answer 2

Let the money invested by Jack and Sristi each in the market be '₹X'.
The amounts at the end of the fourth month will be X(1/2)4 and X-4(15000), respectively.
Similarly, at the end of the sixth month will be X(1/2)6 and X-6(15000).
Given that: X(1/2)4/X(1/2)6 = X-4(15000)/X-6(15000)
4X - 24(15000) = X - 4(15000)
3X = 20(15000)
or, X = 100000
Hence, option A is the correct answer.