Answer: 6
<u>Step-by-step explanation:</u>
Let x represent the number of plates bought for $6
Let y represent the Total number of plates bought = x + 1
<em>Remember that Mrs. Lim bought another plate for $18</em>
Total cost ÷ Total plates = Average Cost

6x + 18 = 8(x + 1)
6x + 18 = 8x + 8
18 = 2x + 8
10 = 2x
5 = x
y = x + 1
= 5 + 1
= 6