Mathematical Reasoning
Matthew has 2½ times as many stickers as Shirley. Find the ratio of Matthew's stickers to Shirley's stickers.
Question 1 · Multiple choice
Question
Matthew has 2½ times as many stickers as Shirley. Find the ratio of Matthew's stickers to Shirley's stickers.
Options
- A.5 : 2
- B.2 : 5
- C.3 : 2
- D.5 : 3
- E.7 : 2
Correct answer
Explanation
Step 1: Convert "2½ times" into a fraction
"Matthew has 2½ times as many stickers as Shirley."
2½ as a fraction = 5/2
So: Matthew = (5/2) × Shirley
Step 2: Write the ratio
Matthew : Shirley = (5/2) × Shirley : Shirley
= 5/2 : 1
Step 3: Remove the fraction by multiplying both parts by 2
= (5/2 × 2) : (1 × 2)
= 5 : 2
A helpful way to picture it: if Shirley has 2 stickers, Matthew has 5 stickers.
Answer: Matthew : Shirley = 5 : 2
| Option | Value | Why it is wrong |
|---|---|---|
| A | 5 : 2 | 2½ = 5/2, so Matthew : Shirley = 5 : 2. ✓ |
| B | 2 : 5 | Reversed the ratio — Shirley : Matthew. ✗ |
| C | 3 : 2 | Confused 2½ with 1½ (= 3/2). ✗ |
| D | 5 : 3 | Used the wrong denominator when converting 2½. ✗ |
| E | 7 : 2 | Used 3½ instead of 2½. ✗ |
