- A9 : 12
- B21 : 28
- C4 : 3
- D3 : 4
Step-by-Step Solution
HCF of 63 and 84 is 21. 63÷21 = 3 and 84÷21 = 4, so the simplest form is 3 : 4. Dividing by only 3 gives 21 : 28 and dividing by only 7 gives 9 : 12 — both are equivalent ratios but neither is in SIMPLEST form. 4 : 3 reverses the order.
Answer: D) 3 : 4