Finding the Cost of Washers in Relation to Bolts

Date: 12/8/95 at 12:46:5
From: Anonymous
Subject: Word Problem 

Jacob Handyman has been told that 50 identical bolts and 20
identical nuts cost $9.10, whereas 30 nuts and 40 identical 
washers cost $4.00. If 10 each of bolts, nuts and washers cost 
$2.70, what is the price of each washer? 

Date: 5/30/96 at 11:19:41
From: Doctor Alex
Subject: Re: Word Problem 

You will have to formulate 3 equations and solve them 
simultaneously to get your answer.

Let bolts be b, nuts be n and washers be w.

From the first statement,

50b + 20n = $9.10

Similarly from the next statements,

30n + 40w = $4.00

I would like you to try to formulate the last equation as 
practice, okay?

The answer should be 4 cents.

-Doctor Alex,  The Math Forum