Two-way tables
The question
| Sold | Left | Total | |
|---|---|---|---|
| Small | 18 | 16 | 34 |
| Large | 30 | 50 | |
| Total | 38 | 46 | 84 |
The Large and Sold number is missing
The Large and Sold number is missing
How it works.
SoldLeftTotalSmall181634Large?3050Total384684
50−30=20
38−18=20
SoldLeftTotalSmall181634Large203050Total384684
- 01
Every number in a two-way table belongs to a row and a column. The gap is in the Large row and the Sold column, so either can find it.
- 02
Along the row first. The Large row adds up to 50, and the other number in it is 30. So the gap is 50 − 30 = 20.
- 03
Down the column as a check. The Sold column adds up to 38, and the other number in it is 18: 38 − 18 = 20. The same 20.
- 04
So the missing number is 20 — the Large row totals 50, and 50 − 30 = 20.