SOLUTION: On Monday, Herold picked up three doughnuts and four large coffees for the office staff. He paid $4.91. On Tuesday Melinda picked up five doughnuts and six large coffess for the
Question 10342: On Monday, Herold picked up three doughnuts and four large coffees for the office staff. He paid $4.91. On Tuesday Melinda picked up five doughnuts and six large coffess for the office staff. He paid #7.59 What is the cost of one doughnut? What is the cost of one large coffee. Answer by gsmani_iyer(201) (Show Source):
You can put this solution on YOUR website! First of all form equations.
Let the cost of 1 doughnut be = x
Let the cost of 1 large coffee = y
So 3x + 4y = $4.91 ........... (1) Monday's purchases
5x + 6y = $7.59 ........... (2) Tuesday's purchase
Eq.(2)* 2, we get
10x + 12y = $15.18 ........... (3)
Eq.(1)* 3, we get
9x + 12y = $14.73 ........... (4)
Eq.(3)-(4), we get
x = $0.45
Now replacing the value of x in Eq.(1), we get
(3*0.45) + 4y = $4.91
= $1.35 + 4y = $4.91
= 4y = $4.91 - $1.35 = $3.56
So y = = $0.89
Hence x = $0.45 and y = $0.89
i.e. cost of large coffee = $0.89 Answer
First form the equations. Then try to eliminate one variable either by multi-
plying or dividing the equation so that at least one variable becomes equal to
the same variable on the 2nd equation. Then you can eliminate that variable
either by adding or subtracting as the case may be. i.e. if the signs are different, then add and if the signs are same, then subtract to remove the particular variable. Then there will be an equation with only one variable which can be solved easily.
I hope this is very clear to you. Try to solve some problems on your own. OK
Best of luck. God bless you.
