L = large
M = Medium
S = Small
L = 3*s
M = 2*s
L + S = 2940
Substitute 3s for L
3s + s = 2940
4s = 2940
s = 2940/4
s = 735
M = 2*S
M = 2* 735
M = 1470
L = 3*S
L = 3*735
L = 2205
You should check this
L + M + S =? 2940
2205 + 735 = 2940 which checks that much of it.