I would love to understand how to solve this problem: The government donated tons of sand to four Cities. City A received 16 1/2 tons of sand, City B received 26 tons of sand, and City C received 24 1/2 tons of sand. The supplier lost the data for City D; however, they know the total for all four cities was 95 tons. How many tons of sand did City D receive?
Can you explain?