Chapter 1.2, Problem 45PPS

(a)

To determine

To find: how much that will cost.

Answer to Problem 45PPS

The cost is $13.50.

Explanation of Solution

Given information:

B’s given $20 in lunch money by her parents once every two weeks. On some days, she packs her lunch, and on other days, she buys her lunch. A hot lunch from the C costs $4.50, and a cold sandwich from the lunch line costs $2.

Calculation:

If we add up total number of lunches B’s will buy in period of next two weeks, we will get number 3. Applying distributive rule will be:

  $\$4.50\cdot \left(\stackrel{firstweek}{\overbrace{2}}+\stackrel{\sec ondweek}{\overbrace{1}}\right)=\$13.50$

Hence, the cost is $13.50.

(b)

To determine

To find: the numbers of cold sandwiches B’s can buy with the amount left over.

Answer to Problem 45PPS

The numbers of cold sandwiches B’s can buy with the amount left over is 3.

Explanation of Solution

Given information:

B’s given $20 in lunch money by her parents once every two weeks. On some days, she packs her lunch, and on other days, she buys her lunch. A hot lunch from the C costs $4.50, and a cold sandwich from the lunch line costs $2.

Calculation:

From part a that B’s already spent $13.50 for the hot lunches. She has a total amount of $20. Therefore, the given equation corresponding amount left.

  $20-13.50=6.50$

A cold sandwich cost $2. Therefore, B’s will be able to buy 3 sandwiches,

  $2\times 3=6$

Hence, the numbers of cold sandwiches B’s can buy with the amount left over is 3.

(c)

To determine

To find: the number of times B’s will have to pack her lunch.

Answer to Problem 45PPS

She can afford 6 school lunches leaves us with total of 4 packs she will need to make herself.

Explanation of Solution

Given information:

B’s given $20 in lunch money by her parents once every two weeks. On some days, she packs her lunch, and on other days, she buys her lunch. A hot lunch from the C costs $4.50, and a cold sandwich from the lunch line costs $2.

Calculation:

She will eat three hot lunches and with left over money buy three more sandwiches in those two weeks, we can calculate total times she will need to pack lunch herself. From Monday to Friday there are 5 days, and in two weeks there are total of 10 school days. Knowing she can afford 6 school lunches leaves us with total of 4 packs she will need to make herself.