JEE Main & Advanced Mathematics Sequence & Series Question Bank Arithmetic Progression

  • question_answer
    If \[a,\ b,\ c,\ d,\ e,\ f\] are in A.P., then the value of \[e-c\] will be  [Pb. CET 1989, 91]

    A) \[2(c-a)\]

    B) \[2(f-d)\]

    C) \[2(d-c)\]

    D) \[d-c\]

    Correct Answer: C

    Solution :

    \[a,\ b,\ c,\ d,\ e,\ f\] are in A.P. So \[b-a=c-b=d-c=e-d=f-e=K\] Where \[K\] is a common difference. Now, \[d-c=e-d\]\[\Rightarrow \]\[e+c=2d\]. \[e\text{--}c+\text{2}c=2d\Rightarrow e-c=2(d-c)\]. Trick: Check by putting \[a=1,\ b=2,\ c=3,\ d=4,\ e=5\] and\[f=6\].


You need to login to perform this action.
You will be redirected in 3 sec spinner