If she buys 60 tiles, the cost at both shops is the same.
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.
Explanation:
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.
