How Many Animals?

There are only two numbers that can be factorised under the constraints to give either one or more than one rabbit. These are:

• 24 = 1 × 3 × 8 = 1 × 4 × 6 = 2 × 3 × 4
• 30 = 1 × 5 × 6 = 2 × 3 × 5

Since knowing whether there is more than one rabbit did not solve the problem, it follows that there is only one rabbit, and Mandy is 24.

Mandy then gave a final clue: “It’s the combination without a prime number in.”