Write and algebraic expression: The tens digit of a number is b and the units digit is twice as big. What is the value of the number in terms of b if the digits are reversed?

Abaseball team drinks 10/4 gallons of water during a game. which mixed number represents the gallons of water consumed? a) 1 1/2 gallons b) 2 1/2 gallons c) 2 3/4 gallons d) 3 1/2 gallons