Respuesta :
Answer:
Lucy bought 4 placemats.
Step-by-step explanation:
Let n be the number of placemats Lucy bought.
1 doormat = $7
1 placemat = $2
n placemats = $2n
Total = $(7+2n)
Total number of objects bought = n+1
Average [tex]=\dfrac{\$(7+2n)}{n+1}[/tex]
So,
[tex]\dfrac{\$(7+2n)}{n+1}=\$3[/tex]
Solve this equation:
[tex]7+2n=3(n+1)\\ \\7+2n=3n+3\\ \\3n-2n=7-3\\ \\n=4[/tex]
Hence, Lucy bought 4 placemats.