Chem 130 3 Question Math Pretest

Problem 1.

Recipe for 6 bad tasting cupcakes:

2 cups of flour

3 teaspoons of salt

2.5 cups of milk

0.5 teaspoons of baking soda

You have 3 gallons of milk

2 teaspoons of baking soda

11 teaspoons of salt

3 lbs. of flour [1 lb. = 1.5 cups]

How many cupcakes can you make?

With 3 lbs Flour you can make:

3 lbs flour x (1.5 cups flour / 1 lb flour) x (6 cupcakes / 2 cups flour) = 13.5 cupcakes

With 11 teaspoons salt you can make:

11 teaspoons salt x (6 cupcakes / 3 teaspoons salt) = 22 cupcakes

With 2 teaspoons of baking soda you can make:

2 teaspoons baking soda x (6 cupcakes / 0.5 teaspoons baking soda) = 24 cupcakes

With 3 gallons of milk you can make:

3 gallons of milk x (16 cups of milk / 1 gallon of milk) x (6 cupcakes / 2.5 cups of milk) = 115.2 cupcakes

So the limiting ingredient is Flour…. You can make 13.5 cupcakes

You have 500 empty diet coke cans.

You can redeem them for 5 cents each.

You must drive 50 miles one way to get to the redemption center.

You car gets 30 miles per gallon.

Gas costs $1.75 per gallon.

How much will you make or lose by returning the cans?

Money Made:

500 cans x (.05 dollars / 1 can) = 25 dollars

Cost:

50 miles x 2 x (1 gallon of gas / 30 miles) x (1.75 dollars / 1 gallon of gas) = 5.83 dollars

Profit = 25 dollars – 5.83 dollars = 19.17 dollars

Betty ran a 10K [6.2 miles] race at 5 miles per hour.

Sally walked at half of Betty’s speed.

How long did it take Sally to walk the 10K race?

Betty: 6.2 miles x (1 hour / 5 miles) = 1.24 hours

Sally: 1.24 hours x 2 = 2.48 hours