Word problem

Question

desmond and Melissa collect cards. They have 92 cards in all. Melissa has three times as many cards as Desmond. How many cards does Desmond have? 

Answer 1

Let d be the number of cards Desmond has and m be the number of cards Melissa has.

 

d + m = 92      (this statement means "desmond and melissa have 92 cards in all)

 

m = 3d            (this statement means "melissa has 3 times as many cards as desmond")

 

With a simple substitution....

 

d + 3d = 92

 

4d = 92

 

d = 23

 

Desmond has 23 cards

 

Keep in mind every time you encounter a word problem of this variety, you should be looking for key terms that relate the unknowns. Has/Have are equivalent to an equals sign, a statement of two (or more) people usually implies those individuals will be variable names.