How many even number in the range between 10 to 120 inclusive are not divisible by 3
Choose the correct choice from the following options:  A) 15  B) 30  C) 31  D) 37  E) 46
We have to find the number of terms that are divisible by 2 but not by 6( as the question asks for the even numbers only which are not divisible by 3)   For 2,   10,12,14...120   using AP formula, we can say 120 = 10 + (n-1) *2   or n=56.   For 6,   12,18,...120   using AP formula, we can say 120 = 12 + (n-1) *6   or n=19.   Hence, only divisible by 2 but not 3 =56-19= 
<gadget id="calculator">56-19</gadget>
<output>37</output>
37. hence, Answer 37
<result>D</result>
How many even number in the range between 10 to 120 inclusive are not divisible by 3