0
$\begingroup$

Ryan invests M dollars in the stock market. After his investment increases by 10%, he takes out \$150 and sets it aside. The remaining investment then decreases by 10%. If the sum of the invested money and the \$150 set aside are 4% larger than the original investment M, by what dollar amount has M increased?

1 Answers 1

1

Initial amount is $M$.

After investment increases by $10 \%$, the amount is $1.1M$.

He takes out $150$ and hence the amount now is $1.1M - 150$.

The remaining amount decreases by $10 \% \implies$ the amount is $0.9 (1.1M - 150) = 0.99 M - 135$

The sum of this and $150$ is $4\%$ larger than the initial amount i.e. $0.99 M - 135 + 150 = 1.04 M \implies0.05M = 15 \implies M = 20 \times 15 = 300$

Hence, the initial amount invested is $\$ 300$.