In a bank, 6% interest is given on the deposited amount. The bank then invests the money in the stock market and is able to earn ₹30,000 for every ₹3,00,000. How much money is the bank earning finally if the total amount deposited in the bank is ₹60,00,000?

Correct — B. Money comes in at one rate and goes out at another, so the bank keeps the gap.

First convert the odd unit: ₹30,000 earned on every ₹3,00,000 is 10%.

Earned on the stock market:
10% of ₹60,00,000 = ₹6,00,000

Paid out to depositors:
6% of ₹60,00,000 = ₹3,60,000

₹6,00,000 − ₹3,60,000 = ₹2,40,000 → option (b).

Why the others are wrong

• (a)
  ₹3,00,000 — ₹3,00,000 is the investment unit the question uses to state the return, not money the bank keeps. It is a scale for the 10% figure, not an income.
• (c)
  ₹6,40,000 — ₹6,40,000 is above the gross stock-market income of ₹6,00,000, so no subtraction can reach it. Nothing in the data earns the bank more than 10%.
• (d)
  ₹3,60,000 — ₹3,60,000 is the interest paid out to depositors — the bank's cost, not its earning. Stopping here answers the outgo and skips the subtraction.

This is a spread question. Two rates act on the same principal, and the answer is the difference.

The first job is to make the rates comparable: ₹30,000 per ₹3,00,000 is 10%, so both sides of the deal are now percentages of the same ₹60,00,000.

Net rate = 10% − 6% = 4%, and 4% of ₹60,00,000 is ₹2,40,000 — a one-line route to the same answer that avoids two large multiplications.

Key facts

• ₹30,000 earned on ₹3,00,000 is a 10% return.
• The bank's margin here is the 4-point gap between the 10% it earns and the 6% it pays.
• 4% of ₹60,00,000 is ₹2,40,000.

Common traps

• Answering ₹6,00,000 or ₹3,60,000 and forgetting one is subtracted from the other
• Applying the 10% to ₹3,00,000 instead of to the full deposit

No directly related past PYQ was found.