Each club member collected 15 boxes of recycling for community service. Let C represent the number of club members and T represent a total number of boxes collected. Which equation models the situation?

T + 15 = C

C15=T

15T = C

15C = T

The equation modelling the situation is:

T = 15C

Of the choices listed here, either

C15=T

or

15C = T

expresses the same relationship. Usually we like to write the coefficient of the variable in front (as in the last choice shown), but that is not required. Either of these expressions means the same as written. (If math operators are missing or exponents are supposed to be involved, that alters things.)