Pencil and Eraser

Algebra Level 1

A pencil and an eraser cost a dollar and ten cents. The eraser costs a dollar more than the pencil. How much does the pencil cost (in cents)?


The answer is 5.

Claire Meng by Claire Meng , 22, USA

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

3 solutions

Michael Fuller
Nov 26, 2015

P e n c i l + E r a s e r = $ 1.10 , P e n c i l + $ 1.00 = E r a s e r Pencil + Eraser ~=~ \$1.10, ~~~~Pencil + \$1.00 ~=~ Eraser

⇒ P e n c i l + ( P e n c i l + $ 1.00 ) = $ 1.10 \Rightarrow Pencil ~+~ ( Pencil + \$1.00 ) ~=~ \$1.10

⇒ P e n c i l = $ 0.05 \Rightarrow Pencil ~=~ \large \$0.05

3 Helpful 0 Interesting 0 Brilliant 0 Confused
Claire Meng
Nov 20, 2015

For some people when they first see this they assume that the pencil is $0.10. The problem says that the eraser is one more dollar. So the pencil has to be $0.05 not $0.10.

1 Helpful 0 Interesting 0 Brilliant 0 Confused

If you were convinced it was 10 cent you're prone to cognitive laziness!

0 Helpful 0 Interesting 0 Brilliant 0 Confused

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...