A litre of orange cordial contains 10% orange juice. How many miillilitres of orange juice must be added to produce a mixture containing 50% orange juice? Could you please explain step by step and explain why the answer won't be 400?

3 answers

Well, because the answer is 800 ml

.1(1000) + x = .5(1000+x)
100 + x = 500 + .5x
.5x = 400
x = 800
the 10% mix has 900 ml of water
So, you will need 900 ml of juice at the end to make it 50%
so, add 800ml of juice

adding 400ml only gives you 500ml of juice in 1400ml of mix, for 5/14 = 35.7% juice
I have the same question Reiny, but how would it be (1000 + x), since the question is mentioning about half a litre, which is 500ml