Question

1+2+3+4+5+6.......+99 what is the quickest way to find the answer Thank u

Answer 1

`1+2+3+4+5+6+\ldots+99=\\(1+99)+(2+98)+\ldots+(49+51)+50=\\49\cdot100+50=\\4950`

Answer 2

Explanation:

Use the formula Sum = (a + L)*n/2

The tricky part is n. That's the number of terms between 1 and 99 inclusive.

n = 99 -1 + 1 = 99

n = 99

a = 1

L = 99

Sum = (1 + 99)*99 / 2

Sum = (100)*99/2

Sum = 4950