Answer:
Number of 7 inch plate = 8
Number of 12 inch plate = 7
Step-by-step explanation:
There are 15 plates in a kitchen cabinet. The diameter of each plate is either 7in or 12in. The diameter of all 15 plates combined is 140in. Which system of equations can be used to find the number of 7in plates, x , and the number of 12in plates, y , that are in the cabinet?
Given that :
Total Number of plates = 15
Diameter of each plate : 7 in or 12 in
Diameter of all 15 plates = 140 in
Let number of 7 in and 12 in diameter plates = x and y respectively ;
x + y = 15 - - (1)
7x + 12y = 140 - - - (2)
x = 15 - y
Substitute x = 15 - y in (2)
7(15 - y) + 12y = 140
105 - 7y + 12y = 140
105 + 5y = 140
5y = 140 - 105
5y = 35
y = 7
From x = 15 - y
x = 15 - 7
x = 8
Number of 7 inch plate = 8
Number of 12 inch plate = 7
