DSQ: Understanding mixture problems Practice Test

Two hydrochloric acid solutions, one of concentration 40% and one of concentration 25%, are mixed together to make a solution of 35% concentration.

How much solution is made?

1. 200 ml of 40% solution is used

2. 100 ml of 25% solution is used

A delivery truck is carrying two types of packages, green boxes and brown boxes. Green boxes weigh 10 lbs each, while brown boxes are 30 lbs each. At the weigh station, the driver notes that his load weighs exactly 400 lbs. How many green boxes does he have in his truck?

1. He is carrying exactly 20 boxes.

2. The driver never loads more brown boxes than green boxes.