Veeru invested Rs. 10,000 at 5% simple annual interest, and exactly after two years, Joy invested Rs. 8,000 at 10% simple annual interest. How many years after Veeru’s investment, will their balances, i.e., principal plus accumulated interest, be equal?

Question

Veeru invested Rs. 10,000 at 5% simple annual interest, and exactly after two years, Joy invested Rs. 8,000 at 10% simple annual interest. How many years after Veeru&rsquo;s investment, will their balances, i.e., principal plus accumulated interest, be equal?

Accepted Answer

12 — Easy Measure time $t$ in years from Veeru's investment. Veeru earns simple interest for $t$ years; Joy starts $2$ years later, so he earns for $(t-2)$ years. Write both balances and set them equal. 1 Write each balance at time $t$. $$\begin{aligned} &	ext{Veeru} = 10000\left(1+\frac{5t}{100}ight)\ &	ext{Joy} = 8000\left(1+\frac{10(t-2)}{100}ight) \end{aligned}$$ 2 Set equal and simplify. Divide both sides by $2000$ to get $5(\cdots)=4(\cdots)$. $$\begin{aligned} &5\left(1+\frac{5t}{100}

CAT 2020 Slot 1 — QA Question 21

Answer & solution