The local toy store has a bin of toy vehicles for sale. the bin holds b bikes and c cars. if the store sells 1/2 of the vehicles in the bin, which expression represents the number of vehicles remaining in the bin?

Given:

A bin of toy vehicles for sale:

b = number of bikes in the bin
c = number of cars in the bin

The store sells 1/2 of the vehicles in the bin. 

The expression which represents the number of vehicles remaining in the bin:

b + c = 0.5a

where a is the initial number of vehicles before selling. 

Letter c i’d say