Question

What is the sum of the multiples of 4 from 16 to 100?

I got n to be 25 but should I use some other value of n because it starts on the 4th multiple?

Answer 1

yeah, the series should be : 16,20,24,...,100
to find the value of n :
an = a1+(n-1)d
100 = 16 + (n-1)4
100 = 4n + 12
4n = 100 - 12
4n = 88
n=22

Answer 2

now, can u calculate of 16+20+24+28+...+96+100 = ....

Answer 3

I got 1276

Answer 4

11 * (16+100) = 11 * 116 = 1276
u are right