If the terms of a series are either2or24and the sum of all the terms D of the series is 124, then which of the following could be the number of2sin the series?  Choose the correct choice from the following answers:
A) 26  B) 29  C) 35  D) 40  E) 48
Ans: A   Solution: we are not certain how many 2 or 24 are there. but as given sum of all the terms is 124 means  24*5= 
<gadget id="calculator"> 24*5</gadget>
<output>120</output>
120 so number of 24 can't be more than 5   so D=24x +2y = 124   24*5 + 2y =124 then y=2   24*4 + 2y = 124 then y=14   24*3 +2y = 124 then y= 26   24*2 +2y =124 then y = 38   24 +2y = 124 then y= 50   26 is the ans.26
<result>A</result>
If the terms of a series are either2or24and the sum of all the terms D of the series is 124, then which of the following could be the number of2sin the series?