If the total number of items sold by A on all the five days is 3600, then the…
2024
If the total number of items sold by A on all the five days is 3600, then the difference between the number of items sold by A on Monday and Friday is:
Answer: D. 440 — Concept: When one entry of a data series in a table (a row or a column) is missing but the total of that whole series is given, the missing entry is recovered…
- A.
640
- B.
450
- C.
420
- D.
440
Show answer & explanation
Correct answer: D
Concept: When one entry of a data series in a table (a row or a column) is missing but the total of that whole series is given, the missing entry is recovered as (given total) minus (sum of the entries that are listed). A comparison that involves the missing entry can only be made after that entry has been recovered.
Application - the column for A across the five days:
Day | Items sold by A |
|---|---|
Monday | 840 |
Tuesday | 720 |
Wednesday | 560 |
Thursday | 1080 |
Friday | not given |
Five-day total | 3600 |
Add A's four listed days: 840 + 720 + 560 + 1080 = 3200 items.
Recover Friday from the five-day total: 3600 - 3200 = 400 items.
Take the difference asked for, Monday minus Friday: 840 - 400 = 440 items.
Cross-check: putting the recovered value back into A's column gives 840 + 720 + 560 + 1080 + 400 = 3600, exactly the five-day total stated in the question, so the Friday value of 400 is consistent. The required difference is 440 items.
Note: only the column for A is involved here. The blank cells in the other columns and the sales of B, C, D and E are not needed; totalling the Friday row instead of A's column, or dropping one of A's listed days before subtracting, changes the recovered Friday value and therefore the difference.