If 945*s is a perfect square then s can be which of the following numbers?
Choose the correct choice from the following options.
A) 21	B) 35	C) 54	D) 105	E) 150
For a number to be a perfect square all the prime factors must be in pairs. So,   Prime factors of 945 are 3 *3 *3 *5 * 7   1) 21 = 3 * 7   2) 35 = 5 * 7   3) 54 = 2 * 3 * 3 * 3   4) 105 = 3 * 5 * 7   5) 150 = 2 * 3 * 5 * 5   So only answer choice D completes the pairing of 3, 5 and 7. It adds a "3", a "5", and a "7" to the prime factors of 945 (3*3*3*5*7) and makes it a perfect square.
<result>D</result>
If 945*s is a perfect square then s can be which of the following numbers?