The number of votes polled in favour of A and C, taken together in January,…
2024
The number of votes polled in favour of A and C, taken together in January, May and September is approximately ______ % less than the number of votes polled in favour of B and D, taken together in March, July and November.
Answer: A. 27 — Concept — In the phrasing “X is p% less than Y”, the quantity written after “less than” is the base of the comparison. The shortfall is always measured…
- A.
27
- B.
37
- C.
44
- D.
18
Show answer & explanation
Correct answer: A
Concept — In the phrasing “X is p% less than Y”, the quantity written after “less than” is the base of the comparison. The shortfall is always measured against that base, so p = (Y − X) ÷ Y × 100. Taking the smaller quantity as the base instead answers a different question (“by what per cent is Y more than X?”) and produces a different number.
Application — Pick out only the cells the stem names and build the two group totals.
Group | Months | Values added (lakh) | Total (lakh) |
|---|---|---|---|
A + C | January, May, September | (1.5 + 3.0) + (1.0 + 2.5) + (2.0 + 3.5) | 13.5 |
B + D | March, July, November | (3.0 + 4.0) + (1.0 + 4.5) + (2.0 + 4.0) | 18.5 |
A and C in January, May and September: 4.5 + 3.5 + 5.5 = 13.5 lakh.
B and D in March, July and November: 7.0 + 5.5 + 6.0 = 18.5 lakh.
Shortfall of the first group behind the second: 18.5 − 13.5 = 5.0 lakh.
The stem says the first total is “less than” the B and D total, so the B and D total (18.5 lakh) is the base.
Required percentage: (5.0 ÷ 18.5) × 100 = 27.03, i.e. approximately 27 per cent.
Cross-check — Work backwards: 27% of 18.5 lakh is 4.995 ≈ 5.0 lakh, and 18.5 − 5.0 = 13.5 lakh, which is exactly the A and C total.
Contrast — Dividing the same 5.0 lakh gap by 13.5 lakh gives (5.0 ÷ 13.5) × 100 ≈ 37, but that answers “by what per cent is the B and D total more than the A and C total?” — the base has been swapped. Dividing by the six-month grand total, or comparing only the two smaller monthly figures, shifts the base again and gives yet another value. Fixing the base from the wording of the stem is the whole skill being tested here.