7.5 litres you can find this by dividing the number by 10, for example let’s use the number 20. you would divide 20 by 10 which is 2 and times it by 7. This is 14. By finding this you have found 70% of 20. now to find 5%, i would divide 20 by 10 once again which is 2 and then i would divide it by 2 which is 1. then you would add the 2 numbers so 14+1 to get 15 therefore 75%of 20=15