Question

Margo can purchase tile at a store for $0.99 per tile and rent a tile saw for $56. At another store she can borrow the tile saw for free if she buys tiles there for $1.69 per tile. How many tiles must she buy for the cost to be the same at both stores?

Answer 1

Let the number of tiles be
x
At the first shop: Cost =
$
0.79
×
x
+
$
24
=
0.79
x
+
24
At the second shop: Cost =
$
1.19
×
x
=
1.19
x
If the cost is the same:
1.19
x
=
0.79
x
+
24

←
solve for x
1.19
x
−
0.79
x
=
24
0.4
x
=
24
x
=
24
0.4
x
=
60
tiles
If she buys less than 60 tiles, then the second shop is cheaper.
If she buys more than 60 tiles, then the first shop is cheaper.