RenukaD wrote:

If x is divisible by 42. Which of the following numbers is definitely a factor of x2? (Choose

all that apply.)

a) 63 b) 33 c) 36 d) 8

It will be helpful if group can explain the answer as well.

Given:

x=42k=2*3*7*k (where

k is an integer) -->

x^2=2^2*3^3*7^2*k^2.

A.

63=3^2*7 is a factor of

x^2;

B.

33=3*11 may NOT be a factor of

x^2 (we don't know whether 11 is a factor

x^2);

C.

36=2^2*3^2 is a factor of

x^2;

D.

8=2^3 may NOT be a factor of

x^2 (

2^2=4 is a factor of

x^2, but we need one more 2 and we don't know whether unknown multiple,

k^2, contains it or not).

Answer: A and C.