Out of her total monthly income, a woman spends 60% on household expenses and 15% on savings. The remaining is spent on other items. What percentage of her income is spent on these other items?

Correct — B. Both given shares are percentages of the same total income, so they add, and all three shares together make 100%.

Household + savings = 60% + 15% = 75%
Other items = 100% − 75% = 25% → option (b).

Check: 60 + 15 + 25 = 100.

Why the others are wrong

• (a)
  35% — 35% would make the three shares 60 + 15 + 35 = 110% of her income, more than she earns. The remainder after 75% is 25%.
• (c)
  20% — 20% makes the shares total 60 + 15 + 20 = 95%, leaving 5% of her income unaccounted for. The remainder must close the gap to 100%.
• (d)
  30% — 30% gives 60 + 15 + 30 = 105% of her income, which is impossible. Household expenses and savings take 75%, so 25% is left.

When every share is quoted as a percentage of one whole, the shares add, and the missing share is 100% minus the rest.

The stem fixes the base in its first words, "Out of her total monthly income", so 60% and 15% are both taken on the full income.

The variant to watch quotes a share as a percentage of the remaining amount. Those percentages cannot be added, because each one shrinks the base before the next is applied.

Key facts

• Shares of one whole always total 100%.
• Household expenses and savings take 60% + 15% = 75% of her income.
• Other items take 100% − 75% = 25%.

Common traps

• Taking 15% of the 40% left after household expenses (6%) and ending at 34%, which misreads "Out of her total monthly income".
• Subtracting only the household share, 100 − 60 = 40%, and forgetting that savings also come out of the same income.

No directly related past PYQ was found.