Which of the following integers doesn't have a divisor greater than 1 that is the square of an integer?
Choose the correct choice.
A) 12 B) 36 C) 100 D) 61 E) 72
Prime Factorization   12=2*2*3=2^2*3. Includes a perfect square of 4.   36=2*2*3*3=2^2*3^2. Includes perfect squares of 4 and 9.   100=2*2*5*5=2^2*5^2. Includes the perfect squares 4 and 25.   61=61*1. 61 is prime, no perfect squares so a possibility.   72= 2*3*2*3*2=6^2*3. Includes perfect square of 36.   28=2*2*7=2^2*7. Includes a perfect square of 4.   All but 61 have a perfect square as a factor so the answer is D.   12=4*3. Perfect square of 4.   36=4*9. Perfect squares of 4 and 9.   100=4*25. Perfect squares 4 and 25.   61=61*1. No perfect squares.   72= 36*2. Perfect square of 36.
<result>D</result>
Which of the following integers doesn't have a divisor greater than 1 that is the square of an integer?