72. 18*4=72
18+18+18+19+23+23+24+24=167
72 but there is such a thing as a CALCULATOR
16 + 16 + 16 + 17 + 18 + 18 + 18 + 19 + 19 + 20 + 20 + 20 + 21 = 238
16 + 16 + 18 + 18 = 68
18 + 18 + 18 = 54
U = 4 x 18 U = 72
It is: 5+13+18 = 36
(13+5)18=13+(5+18)
3818 + 18 = 3836
160
3.33.3