50 cc of 10% acid solution and 100 cc of 4% acid solution should be mixed.
Step-by-step explanation
Suppose, the amount of 10% acid solution is
cc.
As the amount of mixture solution is 150 cc, so the amount of 4% acid solution will be:

Given that, the percentage of acid in the mixture is 6% . So the equation will be.....

So, the amount of 10% acid solution is 50 cc and the amount of 4% acid solution is (150-50)cc = 100 cc