The only prime factors of a number n are 2, 5, 7, and 17. Which of the following could NOT be a factor of n?

Question

A)10

B)20

C)25

D)30

E)34

Answer 1

Favorite Answer

10 = 2 x 5

20 = 2² x 5

25 = 5²

30 = 2 x 3 x 5

34 = 2 x 17

n is not divisible by 30 as it would have to be divisible by 3 also.

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Answer 2

You are not very bright, are you ?  Don't you have a calculator ?  Just TRY them, for god's sake.

2 x 5 x 7 x 17 = 1190

Now try dividing 1190 by each of the given numbers.  (Hint :  there are THREE answers.)

Answer 3

 The only prime factors of a number n are 2, 5, 7, and 17. 

 Which of the following could NOT be a factor of n?

 Answer choice:

 D) 30

Answer 4

D because 3 would also be a prime factor