The usual price of a pen sold at Shop P and Q is $30. During a sale, a discount of 20% is given to every pen sold at Shop P. At Shop Q, a discount of 40% is given to the 4th pen for every 4 pens sold. How much cheaper would it be if Emily buys 11 pens from Shop P instead of Shop Q?
|
Shop P |
Shop Q |
Price of 1 pen |
80% $24 |
100% $30 |
Every 4th pen |
|
60% $18 |
Price of 1 pen from Shop P in percentage
= 100% - 20%
= 80%
Price of 1 pen from Shop P at 20% discount
= 80% x 30
=
80100 x 30
= $24
Cost of 11 pens from Shop P
= 11 x 24
= $264
Price of the 4th pen from Shop Q in percentage
= 100% - 40%
= 60%
Cost of 4th pen at Shop Q
= 60% x 30
=
60100 x 30
= $18
Cost of 1 set of 4 pens at Shop Q
= 30 x 3 + 18
= $108
Number of sets of 4 for pens at Shop Q
= 11 ÷ 4
= 2 r 3
Cost of 2 sets of 4 pens at Shop Q
= 2 x 108
= $216
Cost of 3 pens at Shop Q
= 3 x 18
= $54
Cost of 11 pens at Shop Q
= 216 + 54
= $270
Amount cheaper if Emily buys 11 pens from Shop P instead of Shop Q
= 270 - 264
= $6
Answer(s): $6