How many factors of 2⁴ × 3² × 5 are perfect squares?

Explanation

A square factor needs even exponents: 2 can take 0, 2 or 4 (3 ways), 3 can take 0 or 2 (2 ways) and 5 only 0 (1 way), so 3 × 2 × 1 = 6.