ATQ, Let the mixture in each container be 100 litres. Quantity of type A chemical in 1st container = 100 × 45% = 45 litres. Quantity of type B chemical in 2nd container = 100 × 55% = 55 litres. Quantity of type A chemical in 2nd container = 100 – 55 = 45 litres. Quantity of final mixture = 100 + 100 = 200 litres. Quantity of type A chemical in final mixture = 45 + 45 = 90 litres. Percent of Type A chemical in final mixture = 90/200 × 100 = 45%.