Question

1) In Switzerland the price of gasoline is 1.82 Swiss Francs per liter. How much is this in US dollars per gallon? Use a conversion rate of 0.91 Swiss Francs per US dollar.

2) Suppose that53% of the calories in a chocolate chip cookie are due to fat, and the cookie has 69calories. Given that each gram of fat contains 9.0 calories, how many grams of fat does the cookie contain?

Answer 1

1) 1 gallon = 3.78541 L

0.91 Swiss Francs = 1 US dollar => 1 Swiss Franc = 1/0.91 USD

Price of 1 gallon = Price of 3.78541 L

= 1.82 * 3.78541 Swiss Francs

= 1.82 * 3.78541 * (1/0.91) USD

= 7.57 USD

The answer is 7.57 USD/gallon.

2) Total no. of calories in cookie = 69 cal

No. of calories in cookie due to fat = (53 / 100) * 69 = 36.57 cal

9 calories are contained in 1 g of fat.

Thus 36.57 cal are contained in: (1/9) * 36.57 = 4.06 g of fat

The cookie contains 4.06 g of fat.