a 15 lt mixture contains water with 20 % of alcohol . if 5 more lts of water added to the mixture what is the percentage of alcohol ?
initially the mixture contains 20 % of 15 = 15 * ( 20 / 100 ) = 3 lts of alcohol after mixing another 5 lts of water . . . the total liquid is 20 lts . . so alcohol percentage = ( 3 / 20 ) * 100 = 15 % answer : b
multiply(divide(multiply(divide(20, const_100), 15), add(15, 5)), const_100)