A pen and a book both cost $2.20 but the book cost $2.00 more than the pen. What is the price of the pen?

Question

A pen and a book both cost $2.20 but the book cost $2.00 more than the pen. What is the price of the pen?

Answer 1

At first glance it seems that the book cost $2 and the pen costs $0.20, but then you see that the book would  be only $1,80 more than the pen.

 

P + B = $2.20

B = P + $2

 

Substituting the second equation into the first we get

 

P + P + $2 = $2.20

2P =  $0.20

P = $0.10

 

$0.10 + B = $2.20

B = $2.10