Answer:x
=
5
toppings
Step-by-step explanation:Total cost of cheese pizza:
$
10.75
Any additional topping adds:
+
$
1.25
So a cheese pizza with
1
additional topping is:
$
10.75
+
$
1.25
=
$
12.00
A cheese pizza with
2
additional toppings is:
$
10.75
+
$
1.25
+
$
1.25
=
$
10.75
+
2
×
$
1.25
=
$
13.25
A cheese pizza with
3
additional toppings is:
$
10.75
+
$
1.25
+
$
1.25
+
$
1.25
$
10.75
+
3
×
$
1.25
=
$
14.50
If you pay attention to the pattern you can see that, for any number of toppings, say
x
toppings, the price is going to be:
$
10.25
+
x
×
$
1.25
We are told the final cost is
$
17.00
. That is
$
10.25
+
x
×
$
1.25
=
$
17.00
Subtract
$
10.25
from both sides
$
10.25
−
$
10.25
+
x
×
$
1.25
=
$
17.00
−
$
10.25
x
×
$
1.25
=
$
6.25
Divide both sides by
$
1.25
x
×
$
1.25
$
1.25
=
$
6.25
$
1.25
x
=
5
The quotient of 5 1/4 and 3/16 is 28
To answer this you can use a guess and check strategy.
Start with 5 minutes using it (25% lost) and 10 minutes charging (20% gained).
Try 7 minutes using it (35% lost) and 14 minutes charging (28%).
Next, 9 minutes (45%) and 18 minutes(36%).
10 minutes (50%) and 20 minutes (40%). This is the difference.
She used it for 10 minutes and charged it for 20 minutes.
24 times 3= 72+4=76+14=90
^
