Question

find two consecutive multiple of 3 whose sum is 415

Answer 1

let the consecutive multiples of 3 be x and x+3
respectively.
then,
x+(x+3)=415
2x+3=415
2x=415-3
2x=412
x=412/2
=206

so, the numbers are 206 and 209 respectively.

HOPE IT HELPS!