# Percentage question #3.

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• Oct 21st 2009, 07:55 PM
dtay
Percentage question #3.
Question :

Jane bought 5kg of grapes and 10kg of cherries at \$82.50.
If Jane were to buy 10kg of grapes and 5kg of cherries, she would only pay \$75

If 100grams of grapes cost 45 cents, find the cost of 1kg of cherries.
• Oct 21st 2009, 08:11 PM
Wilmer
I don't see the equations you set up to solve this.
Did you forget to post them?
• Oct 21st 2009, 08:15 PM
Rapha
Hi.

Quote:

Originally Posted by dtay
Question :

Jane bought 5kg of grapes and 10kg of cherries at \$82.50.
If Jane were to buy 10kg of grapes and 5kg of cherries, she would only pay \$75

If 100grams of grapes cost 45 cents, find the cost of 1kg of cherries.

"Jane bought 5kg of grapes and 10kg of cherries at \$82.50."

5*x + 10*y = 82.50 (1), where x is the price of grapes/kg; y price of 1kg cherries.

"If Jane were to buy 10kg of grapes and 5kg of cherries, she would only pay \$75"

10*x+5y = 75 (2)

"If 100grams of grapes cost 45 cents, find the cost of 1kg of cherries."

1kg grapes cost 10*0.45 = \$4.5 = x. Now substitute this into (1) and (2), you get y=\$6, so 1kg of cherries cost \$6

Any questions?

Yours
Rapha
• Oct 21st 2009, 08:19 PM
comssa
Let g=#grapes
Let c=#cherries

Equation 1: 5g+10c=82.5
Equation 2: 10g+5c=75
multiply equation 1 by 2

10g+20c=165
- 10g+5c=75
-----------------
15c=90
c=6
1kg of cherries costs 6 dollars.

(Rapha beat me to it lol)