DRDO Multi tasking staff Model paper 1

Tips & Tricks
Let the first number be a
Common difference = 2
Total sum of 17 even integers = 17 × 50 = 850
Sum of n terms of an AP = (n/2)(2a + (n - 1)d)
⇒ 850 = (17/2) × (2a + 16 × 2)
⇒ 2a + 32 = 100
⇒ a = 34
∴ Largest number = a + (n - 1) d = 34 + 16 × 2 = 66
Short trick
If we take average of 17 numbers then middle number i.e. 9th number = average of 17 numbers = 50
Now, largest number = 9th number + (n × d) = 50 + 8 × 2 = 66.