Which of the following numbers does not divide exactly into 98 ?
(A) 2
(B) 4
(C) 7
(D) 14
(E) 49
Solution 1

Since $98 \div 2=49,98 \div 7=14,98 \div 14=7,98 \div 49=2$, and $98 \div 4=24.5$, then the one of the five choices which does not divide exactly into 98 is 4 .

## Solution 2

The prime factorization of 98 is $98=2 \times 7 \times 7$.

Of the given possibilities, only $4=2 \times 2$ cannot be a divisor of 98 , since there are not two 2 's in the prime factorization of 98 .

ANsWER: (B)