How many odd integers from 1 to 100 (both inclusive) have odd number of factors?
Choose the correct choice from the following choices.
A) 13  B) 14  C) 5  D) 6  E) 7
Integers having odd number of factors will be perfect squares. Odd numbers will have odd perfect squares. Thus, the possible values for the perfect squares are :   1,9,25,49,81 and the corresponding integers are 1,3,5,7,9 (more than 4). Thus 5 is the correct answer .
<result>C</result>
How many odd integers from 1 to 100 (both inclusive) have odd number of factors?