Question

If S is the sum of integers from 51 to 150 and T is the sum of integers from 151 to 250, what is the value of S-T?

Answer 1

Observe that
151 -51 = 100
152 - 52 = 100
...
250 - 150 = 100

Answer 2

okay

Answer 3

though probably you should look at it like this:

51-151 = -100
52-152 = -100
...

Answer 4

ok

Answer 5

So, what's your answer?

Answer 6

-10,000
by using formula

Answer 7

Very good.