Now, the percentage figures of say, 70%, 95% and so on, we'll use the decimal format of the, thus 70% is just 70/100 or 0.7 and 95% is just 95/100 or 0.95 and so on
so
whatever "x" and "y" amounts are, we know, they must add up to 160 pints
thus x + y = 160
now, whatever the concentrated amount of solute in the mixture, we know they must add up to 160*0.85 or 136
thus 0.7x + 0.95y = 136
thus
solve for "x", to see how much of the 70% pure juice will be needed
what about "y"? well, y = 160 - x
so
whatever "x" and "y" amounts are, we know, they must add up to 160 pints
thus x + y = 160
now, whatever the concentrated amount of solute in the mixture, we know they must add up to 160*0.85 or 136
thus 0.7x + 0.95y = 136
thus
solve for "x", to see how much of the 70% pure juice will be needed
what about "y"? well, y = 160 - x