the proportion of water to alcohol in solution a is 4 : 1 and the proportion of water to alcohol in solution b is 3 : 1 . if an equal amount of each solution is mixed together , what is the concentration of alcohol in the new solution ?
"let v be the total volume of the new solution . then a volume of v / 2 was added from each solution a and b . the amount of alcohol added to the new solution was : ( 1 / 5 ) ( v / 2 ) + ( 1 / 4 ) ( v / 2 ) = v / 10 + v / 8 = 9 v / 40 . the concentration of alcohol is 9 / 40 = 22.5 % the answer is d ."
multiply(divide(add(1, 1), add(add(4, 3), add(1, 1))), const_100)