tolong bantu jawab ya....

6. p. total besi = 80m = 800cm

K = 12 . r
= 12 . 15
= 180
utk membuat 1 kubus memerlukan besi sepanjang 180cm

800/180 = 4

maka dapat dibuat sebanyak 4 kubus

sisa besi :
4 . 180 = 720

800 - 720 = 80cm

7. jmlh p. rusuk = 240
r = 240/12
= 20

V = r^3
= 20^3
= 8000
= 8 liter

8. r1 = m
r2 = 3/4m

V= r^3

V1 : V2
m^3 : (3/4m)^3
m^3 : 9/16m^3
1 : 9/16
16 : 9