Didn't answer all because I got lazy and I think you should try and do the rest yourself. Did this in 5 mins, try putting more effort into your homework. This is basic mathematics.
Hope this helps you :))))))
1000 ml costs £3.50
200 is 1/5 of 1000 so it will be £0.7
The total amount is 0.75 inches or 3/4 inches.
3(2x-4)=2(x+4)
6x-12=2x+8
6x-2x=8+12
4x=20
x=20/4
x=5