To find out how many quarts there are in 40 gallons, we simply need to know how many quarts there are in one gallon. As the name implies, there are 4 quarts in one gallon, so we simply need to multiply 4 * 40 to find the amount of quarts in 40 gallons.
4 * 40 = 160
There are 160 quarts in 40 gallons.
Hope that helped! =)
