how many kg of pure salt must be added to 100 kg of 10 % solution of salt and water to increase it to a 15 % solution ?
amount salt in 100 kg solution = 10 * 100 / 100 = 10 kg let x kg of pure salt be added then ( 10 + x ) / ( 100 + x ) = 15 / 100 200 + 20 x = 300 + 3 x 17 x = 100 x = 5.8 answer is a
divide(subtract(15, 10), subtract(const_1, divide(15, 100)))