If P = 22 + 62 + 102 + 142 + … 942 and Q = 12 + 52 + 92 + … 812, then what is the value of P – Q?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 (i.e. 26075)
P = 22 + 62 + 102 + 142 + ..... 942
No. of terms = 
=24
Q = 12 + 52 + 92 + ..... 812
No. of terms = 
= 21
(P – Q) = (22 – 12) + (62 – 52) + ..... (822 – 812) + 862 + 902 + 942
(P – Q) = (3 + 11 + 19 ..... + 163) + 7396 + 8100 + 8836
(P – Q) = 21 × 83 + 24332
= 26075