Question

Find the sum of all the multiples of 4
from 1 to 120​

Answer 1

$\underline{\textbf{Given:}}$

$\textsf{Multiples of 4 from 1 to 120}$

$\underline{\textbf{To find:}}$

$\textsf{Sum of all the multiples of 4 from 1 to 120}$

$\underline{\textbf{Solution:}}$

$\underline{\textsf{Formula used:}}$

$\boxed{\mathsf{1+2+3+\;.\;.\;.\;.\;.\;.+n=\dfrac{n(n+1)}{2}}}$

$\textsf{Multiples of 4 from 1 to 120 are 4,8,12,16. . . . . . . .120}$

$\textsf{Required sum}$

$\mathsf{=4+8+12+16+\;.\;.\;.\;.+120}$

$\mathsf{=4(1+2+3+4+\;.\;.\;.\;.+30)}$

$\mathsf{=4{\times}\dfrac{30{\times}31}{2}}$

$\mathsf{=2{\times}\dfrac{30{\times}31}{1}}$

$\mathsf{=60{\times}31}$

$\mathsf{=1860}$

$\therefore\textbf{The sum of all multiples of 4 from 1 to 120 is 1860}$

$\underline{\textbf{Find more:}}$