Solutions A and B contain acid and water in the ratios 4 ∶ 5 and 5 ∶ 7, respectively. Three litres of A is mixed with 5 litres of B. In 960 ml of this solution, how much (in ml) acid should be mixed so that the ratio of acid and water becomes 1 ∶ 1 in the resulting solution?
1
136
2
130
3
140
4
144