Expert: Bobby Soltani - 3/27/2006

Question
peter and sandra have collected 65 postcards of famous bridges.  peter has 5 more postcards than Sandra.  How many does each person have?


Answer
Hi Thomas,

Let the number of postcards that peter collected be "p" and the number of postcards sandra collected be "s".  From the first sentence, we can write

p + s = 65

From the second sentence, we can write

p = s + 5

Since p = s + 5, we can substitute s + 5 in for p in the first equation.

s + 5 + s = 65

now we have an equation in s only, so we can solve for it.

2s + 5 = 65

subtract 5 from both sides

2s = 60

divide both sides by 2

s = 30

Since we know that p = s + 5, and that s = 30, we can solve for p

p = 30 + 5

p = 35

So, peter has 35 cards and sandra has 30 cards.  Let me know if you have any questions.

Bobby