Question

Ralph and Jody go to the shop to buy potato chips and candy bars.

Ralph buys 3 bags of potato chips and 4 candy bars. He spends

Jody buys 4 bags of potato chips and 2 candy bars. She spends $3.00.

Later Clancy joins Ralph and Jody and asks to buy one bag of potato chips and one candy bar from

them. They need to work out how much he should pay.

Ralph writes

3p+ 4b = 375

1. If p stands for the cost, in cents, of a bag of potato chips and b stands for the cost, in cents, of a

candy bar, what does the 375 in Ralph's equation mean?

Answer 1

375 represents the amount Ralph paid for 3 bags of potato and 4 candy bars

Bag of potato = 45 cent

Candy = 60 cents

Explanation:

375 represents the amount Ralph paid for 3 bags of potato and 4 candy bars

3p + 4b = 375 - - (1)

4p + 2b = 300 ---(2)

From (2)

4p = 300 - 2b

p = 75 - 0.5b

Put b = 75 - 0.5b

3(75 - 0.5b) + 4b = 375

225 - 1.5b + 4b = 375

225 + 2.5b = 375

2.5b = 375 - 225

2.5b = 150

b = 150 / 2.5

b = 60

3p + 4(60) = 375

3p + 240 = 375

3p = 375 - 240

3p = 135

p = 45

Bag of potato = 45 cent

Candy = 60 cents