Book and pen

Algebra Level 2

A book and a pen together cost $1.10. The book costs $1 more than the pen. How much does the book cost?

2 solutions

Hung Woei Neoh
Jul 1, 2016

This is one of the top 5 most asked questions I have seen on Brilliant. Be it cup and ball or book and pen.

Let the price of the book be $x$ . The price of the pen is then $x-1$ . Both of them add up to $\$1.10$ :

$x+(x-1)=\$1.10\\ 2x=\$2.10\\ x=\boxed{\$1.05}$

Abdullah Mughal
Jul 1, 2016

let the cost of the pen = x --> the book costs 1 + x

x + 1 + x = 1.10

x = $0.05 --> book costs 1 + x = $1.05