Question

The sum of two consecutive numbers is S.The square of larger minus the square of smaller number is
(a)S power 2 (b)2S (c)S (d)S+1
please  tell the question step by step and explain and also try to tell fast.

Answer 1

Consider two consecutive numbers like 5 and 6
5+6=11=S
larger number is 6 and smaller is 5
their squares are 36 and 25
36-25=11=S
option is c

Answer 2

let the smaller number is Tn and larger number is Tn+1 
 given  Tn + Tn+1 = s  
 numbers are consecutive hence Tn+1 - Tn = 1
Tn+1∧2 -Tn∧2  = (Tn+1 - Tn )(Tn+1 + Tn )
                       = 1*s
                       = s
    hence  (c)  is correct