Problem One
Your base number is whatever 6 lube jobs would bring in. Then you have to get to 32.50 to calculate the discount. You are selling 6 tickets for 6.50
Total = 6.50 * 6 = 39.00 dollars.
This is a discount problem which means that you have to multiply by a percentage to get the number down to 32.50
39*(x/100) = 32.50 Multiply by 100
39 * x = 3250 Divide by 39
x = 3250 / 39 = 83.3%
But what is that 83.3%? It is not the discount. It is the% of 39 that 32.5 represents. So we have to take 83.3% from 100% to get the discount.
100% = 83.3 = 16.7% That is the discounted amount
Proof
39*16.7/100 = 6.51
If you take 6.51 away from 39, you ought to come pretty close to 32.50
39 - 6.50 = 32.50 Just as we predicted.
Problem Two
Set up a Proportion
85 customers / 50 minutes = 200 / x Cross multiply
85x = 50 * 200
85x = 10000 Divide by 85
x = 10000 / 85 = 118 minutes which is just about 2 hours. Somebody is going to be awfully hungry by the time you are done.
Problem Three.
Present area (assuming a shape whose area is 60*50) = 3000 square feet.
You want to have an area that is 20% larger. The base number here is 3000 square feet.
To get 20% of the base number you just take 20% of the 3000
Increase = 20/100 * 3000 = 60000/100 = 600
That's not what is asked for. They want the new total area.
3000 + 600 = 3600 <<< Answer
