- ANo — a rational number must have a NON-ZERO denominator, and is not defined
- BYes — 9 and 0 are both integers, so fits the form p/q
- CYes — is just another way of writing 0
- DNo — 9 and 0 share no common factor, so it cannot be simplified
Step-by-Step Solution
The definition is p/q with p, q integers AND q not equal to 0. Sameer stops at "both are integers" and forgets the second half of the rule, so is not defined and is not rational. Note the reverse case IS fine: is a perfectly good rational number — zero is only banned in the denominator.
Answer: A) No — a rational number must have a NON-ZERO denominator, and is not defined