By solving a system of equations we will see that the best pair to buy is A and C.
<h3>
Finding the equations:</h3>
Here we have 3 potatoes, A, B, and C. Let's use these variables to define the weight of each potato.
Then, from the given information, we know that:
A + C = 500g
B + C = 400g
A + B = 300g
Then we have a system of equations, to solve it, first we isolate one of the variables in one of the equations. I will isolate A on the first one:
A + C = 500g
A = 500g - C
Now we can replace that in the third equation, now we have:
B + C = 400g
500g - C + B = 300g
Now we do the same thing, this time I will isolate C.
C = 400g - B
Let's replace this on the other equation:
500g - (400g - B) + B = 300g
500g - 400g + 2*B = 300g
100g + 2*B = 300g
B = (300g - 100g)/2 = 100g
So potato B weighs 100g.
We can use that to find the weight of the other two:
C = 400g - B = 400g - 100g = 300g
A = 500g - 300g = 200g
<h3>What pair should Graham buy?</h3>
He wants 200g of potato, so he should buy one pair that includes potato A, which weight exactly 200g. And to get the most of his money, he should buy the pair that contains potato A and that weighs more. So the best pair will be A and C.
If you want to learn more about systems of equations, you can read:
brainly.com/question/13729904