SOLUTION: A pencil and eraser cost total of 15 naira. What is the cost of 60 erasers. If one pencil cost 5 naira?

Question 1167930: A pencil and eraser cost total of 15 naira. What is the cost of 60 erasers. If one pencil cost 5 naira?
Found 2 solutions by Theo, MathTherapy:
Answer by Theo(13342) (Show Source): You can put this solution on YOUR website!
let p equal the cost of one pencil.
let e equal the cost of one eraser.

your equation is p + e = 15

if the cost of 1 pencil is 5 naira, then:

p + e = 15 becomes 5 + e = 15

start with:
5 + e = 15
subtract 5 from both sides of the equation to get:
e = 15 - 5
combine like terms to get:
e = 10

that's the price of 1 eraser.

when 60 erasers are bought, ....

cost = 60 * 10

solve for cost to get:

cost = 600 naira.

Answer by MathTherapy(10552) (Show Source): You can put this solution on YOUR website!

A pencil and eraser cost total of 15 naira. What is the cost of 60 erasers. If one pencil cost 5 naira?

One pencil costs 5 naira
One pencil and one eraser cost 15 naira
Therefore, cost of one eraser = 15 - 5 = 10 naira
Cost of 60 erasers:
RELATED QUESTIONS
if five pencils and three erasers cost 65 cents, and three pencils and two erasers cost... (answered by lwsshak3)
seven pencil and five eraser costs $11.60, whereas 5 pencil and 3 eraser cost $7.60.... (answered by rapaljer)
Five pencils and three erasers cost 65 cents. Three pencils and two erasers cost 40... (answered by Nate)
Five pencils and three erasers cost 65 cents. Three pencils and two erasers cost 40... (answered by checkley77)
A pencil costs X naira and a rubber costs 40 naira more than a pencil. Find the cost of a (answered by mananth)
The cost of pencil is 25 paise more than the cost of a eraser if the cost of 8 pencils... (answered by ikleyn)
The cost of a pencil is 25 cents more than the cost of a eraser. If the cost of 8 pencils (answered by richwmiller)
4. The local store sells individual pencils and erasers. Two pencils and an eraser would (answered by checkley77)
The cost of four pencil and two eraser is Rs10 while the cost of 6 pencil and 3 eraser is (answered by Fombitz)