Question

If Simon wishes to make 450ml of squash how much concentrate and water should he use 2 parts concentrate to 7 parts water

Answer 1

we know that
squash is ------> 2 parts concentrate to 7 parts water
so
2+7----> 9 parts
concentrate--------> (2/9)*450 ml-----> 100 ml
water----------------> (7/9)*450 ml-----> 350 ml

the answer is
100 ml of concentrate and 350 ml of water