Question

The product of 5✓27 and would yield a rational number.

✓12
✓9
4✓2
✓15

Answer 1

5√27 = 5·√(9·3) = 5·3√3 = 15√3.
To get a rational product we need another √3 factor. √12 = √(4·3) = 2√3, and
15√3 · 2√3 = 15·2·3 = 90 (rational).

The other choices leave a leftover irrational factor, so the correct answer is √12.