Question

The dishes have been sorted into cups and plates. The number of plates is four less than two times the number of cups. The dishes are 60% plates. How many cups are there?

a) 3
b) 6
c) 8
d) 9

Answer 1

Option C) 8 cups

Explanation:

Let

x----> the number of cups

y ---> the number of plates

we know that

y=2x-4 -----> equation A

60%=60/100=0.60

y=0.60(x+y) ----> equation B

Substitute equation A in equation B and solve for x

2x-4=0.60(x+2x-4)

2x-4=0.6x+1.2x-2.4

2x-4=1.8x-2.4

2x-1.8x=4-2.4

0.2x=1.6

x=1.6/0.2

x= 8 cups