9. Mark drinks one cup of coffee everyday. He orders a coffee from Dunkin Donuts and it costs him $3.50 everyday. He is starting to think that he might buy a Keurig and k-cups instead. The Keurig is $150 and each k-cup costs $0.50. How many cups of coffee will it take for the cost at Dunkin Donuts to be the same as having a Keurig and k-cups?

50 cups of coffee

Step-by-step explanation:

Let x represent the number of cups of coffee that it will take for the cost at Dunkin Donuts to be the same as having a Keurig and k-cups.

He orders a coffee from Dunkin Donuts and it costs him $3.50 everyday. It means that the cost of ordering x cups would be 3.5x.

The Keurig is $150 and each k-cup costs $0.50. It means that the cost of ordering x cups would be 150 + 0.5x.

For the ordering cost to be the same, it means that

3.5x = 150 + 0.5x

3.5x - 0.5x = 150

3x = 150

x = 150/3

x = 50

all three statements are true

step-by-step explanation:

a shipping fee of 5% is charged online with every item purchased online

first let's just take each option and calculate them based on this, to see if the answers matched

keith buys a 40 dollar book

40 x 0.05 = 2

therefore there will be a two dollar fee on keith's book

40 + 2 =42

the first statement is true

a chair costs $80

80 x 0.05 = 4

80 + 4 = 84

the second statement is true

george buys a 20 dollar calculator

20 x 0.05 = 1

20 + 1 = 21

the third statements are true

all three statements are true