Question 696498
20/900=x/1350 cross multiply.
900x=20*1350
900x=27000
x=27000/900
x=30 burgers can be bought.
4:7=x:5
7x=4*5
7x=20
x=20/7 ans.

18:9=19:x
9x=18*19
9x=342
x=342/9
x=38 ans.

Ill leave the rest for you to practice with.

9:x=24:88   

x:12=42:63