Question

Could you please try to help me and my grandson with this problem?

Answer 1

To match up the given data:

1. Find the discount (in dollars) that each original price would have with each percentage of discount:

Multiply the original price by the discount (in decimals):

Original price: $24

`\begin{gathered} 24*0.2=4.8 \\ 24*0.3=7.2 \\ 24*0.4=9.6 \end{gathered}`

Original price: $35

`\begin{gathered} 35*0.2=7 \\ 35*0.3=10.5 \\ 35*0.4=14 \end{gathered}`

Original price: $30

`\begin{gathered} 30*0.2=6 \\ 30*0.3=9 \\ 30*0.4=12 \end{gathered}`

2. Find the discounted price for each one of the possibilities above:

Original price: $24

`\begin{gathered} 24-4.8=19.2 \\ 24-7.2=16.8 \\ 24-9.6=14.4 \end{gathered}`

Original price: $35

`\begin{gathered} 35-7=28 \\ 35-10.5=24.5 \\ 35-14=21 \end{gathered}`

Original price: $30

`\begin{gathered} 30-6=24 \\ 30-9=21 \\ 30-12=18 \end{gathered}`

3. Match up coincidences.

For the original price of $24; there are not coincidences wit the discounted prices; let this to the end.

For the original price of $35; there is a coincidence: Discounted 40% you get a discounted price of $21

For the original price of $30 (as the discounted price of $21 is taken) the coincidence is: Discounted 20% you get a discounted price of $24

Then, the % that match the original price of $24 is 30% and the missing data is a discounted price of $16.8

Final answer: