Mathematics for Machine Technology

John C. Peterson, Robert D. Smith

Chapter 25 Achievement Review—Section Two - all with Video Answers

Educators

Chapter Questions

00:49

Problem 1

Express these ratios in lowest fractional form.
$15: 32$

Zain Haider

Numerade Educator

00:17

Problem 2

Express these ratios in lowest fractional form.
$46: 12$

Elizabeth Xu

Numerade Educator

00:33

Problem 3

Express these ratios in lowest fractional form.
$12: 46$

Sanchit Gogia

Numerade Educator

00:42

Problem 4

Express these ratios in lowest fractional form.
$27 \mathrm{~mm}: 45 \mathrm{~mm}$

Dushyant Barot

Numerade Educator

00:31

Problem 5

Express these ratios in lowest fractional form.
$21 \mathrm{ft}: 33 \mathrm{ft}$

Michael Jacobsen

Numerade Educator

00:31

Problem 6

Express these ratios in lowest fractional form.
45 in. : 27 in.

Michael Jacobsen

Numerade Educator

00:55

Problem 7

Express these ratios in lowest fractional form.
$\frac{1}{4}$ to $\frac{1}{2}$

Brandon Fox

Numerade Educator

00:21

Problem 8

Express these ratios in lowest fractional form.
16 to $\frac{2}{3}$

Brandon Fox

Numerade Educator

01:01

Problem 9

Express these ratios in lowest fractional form.
$\frac{1}{4} \mathrm{~h}$ to $25 \mathrm{~min}$

Jerelyn Nevil

Numerade Educator

00:37

Problem 10

Express these ratios in lowest fractional form.
$2 \mathrm{ft}$ to $8 \mathrm{in}$.

Sanchit Gogia

Numerade Educator

The cost and selling price of merchandise are listed in the following table. Determine the cost-to-selling price ratio and the cost-to-profit ratio.
$$
\begin{array}{|c|c|c|c|}
\hline \text { Cost } & \text { Selling Price } & \begin{array}{c}
\text { Ratio of Cost } \\
\text { to Selling } \\
\text { Price }
\end{array} & \begin{array}{c}
\text { Ratio of Cost } \\
\text { to Profit }
\end{array} \\
\hline \$ 60 & \$ 96 & & \\
\hline \$ 105 & \$ 180 & & \\
\hline \$ 18 & \$ 33 & & \\
\hline \$ 204 & \$ 440 & & \\
\hline
\end{array}
$$

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06:30

Problem 12

Bronze is an alloy of copper, zinc, and tin with small amounts of other elements. Two types of bronze castings are listed in the table below with the percent composition of copper, tin, and zinc in each casting. Determine the ratios called for in the table.
graph cant copy

Md Mohibullah

Auburn University Main Campus

Problem 13

Solve for the unknown value in each of the following proportions and check. Round the answers to 3 decimal places where necessary.
a. $\frac{P}{12.8}=\frac{3}{2}$
$\longrightarrow$
e. $\frac{6.5}{M}=\frac{8.2}{41}$
b. $\frac{3.6}{0.9}=\frac{E}{2.7}$
$\longrightarrow$
f. $\frac{22.517}{13.503}=\frac{1.297}{x}$
c. $\frac{H}{\frac{1}{4}}=\frac{\frac{1}{2}}{\frac{3}{8}}$
d. $\frac{7}{6}=\frac{C}{12}$
$\longrightarrow$
g. $\frac{20.021}{5.773 T}=\frac{1.892}{4.518}$
h. $\frac{10.360}{7.890}=\frac{2.015}{N}$

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01:18

Problem 14

Analyze each of the following problems to determine whether the problem is a direct or inverse proportion and solve. Round the answers to 3 decimal places where necessary.
a. A reamer tapers 0.0975 inch along a 3.2625 -inch length. What is the amount of taper along a 2.1250 -inch length?
b. A machine produces 2550 parts in 8.5 hours. How many parts are produced by the machine in 10 hours?
c. Of two gears that mesh, one gear with 12 teeth revolves at $420 \mathrm{rpm}$. What is the revolutions per minute of the other gear, which has 16 teeth?

Cory Kuzinski

Numerade Educator

03:53

Problem 15

Express each value as a percent.
a. 1 $\qquad$ b. $1 \frac{1}{2}$

c. $2 \frac{3}{4}$ $\qquad$ d. 0.5
$\qquad$
$\qquad$

Lourence Gonhovi

Numerade Educator

01:48

Problem 16

Express each value as a percent.
a. 0.72 $\qquad$ b. 2.037 $\qquad$ c. $\frac{1}{25}$ $\qquad$ d. 0.0003 $\qquad$
17. Express each percent as a decimal fraction or mixed decimal.
a. $19 \%$ $\qquad$ b. $0.7 \%$ $\qquad$ c. $\frac{3}{4} \%$ $\qquad$ d. $310 \frac{3}{10} \%$ $\qquad$

Catt Huth

Numerade Educator

03:53

Problem 18

Express each percent as a common fraction or mixed number.
a. $30 \%$ $\qquad$ b. $140 \%$ $\qquad$ c. $12.5 \%$ $\qquad$ d. $0.65 \%$

Lourence Gonhovi

Numerade Educator

01:41

Problem 19

Find each percentage. Round the answers to 2 decimal places when necessary.
a. $15 \%$ of 60 $\qquad$ f. $130 \%$ of 212 $\qquad$
b. $3 \%$ of 42.3 $\qquad$
c. $72.8 \%$ of 120 $\qquad$ g. $12 \frac{1}{2} \%$ of 32 $\qquad$
d. $0.7 \%$ of 812 $\qquad$ h. $\frac{1}{4} \%$ of 627.3 $\qquad$ e. $42.6 \%$ of 53.76 $\qquad$
$\qquad$

Shahab Ullah

Numerade Educator

03:53

Problem 20

Find each percent (rate). Round the answers to 2 decimal places when necessary.
a. What percent of 10 is 2 ? $\qquad$ e. What percent of 2.84 is 0.8 ? $\qquad$
b. What percent of 2 is 10 ? $\qquad$ f. What percent of $12 \frac{1}{4}$ is 3 ? $\qquad$ c. What percent of 88.7 is 21.9 ? $\qquad$
d. What percent of 275 is 108 ? $\qquad$ g. What percent of 312 is 400.9 ? $\qquad$

Lourence Gonhovi

Numerade Educator

03:11

Problem 21

Find each base. Round the answers to 2 decimal places when necessary.
a. 20 is $60 \%$ of what number?
e. 9.3 is $238.6 \%$ of what number?
b. 4.1 is $24.9 \%$ of what number?
f. 0.84 is $2.04 \%$ of what number?
c. 340 is $152 \%$ of what number?
g. $\frac{3}{4}$ is $123 \%$ of what number?
d. 44.08 is $73.5 \%$ of what number?

Erika Bustos

Numerade Educator

03:53

Problem 22

Find each percentage, percent (rate), or base. Round the answers to 2 decimal places when necessary.
a. What percent of 24 is 18 ?
g. $72.4 \%$ of 212.7 is $\qquad$
b. What is $30 \%$ of 50 ?
h. What percent of 228 is 256 ?
c. What is $123.8 \%$ of 12.6 ?
i. 51.08 is $88 \%$ of what number?
d. 73 is $82 \%$ of what number? $\qquad$ j. 36.5 is $\qquad$ $\%$ of 27.6 .
e. What percent of $10 \frac{1}{2}$ is 2 ? $\qquad$ k. $2 \frac{1}{4} \%$ of 150 is $\qquad$
f. $\qquad$ is $48 \%$ of 94.82 . $\qquad$ $?$ $\qquad$ is $18 \%$ of 120.66 .

Lourence Gonhovi

Numerade Educator

01:20

Problem 23

The carbon content of machine steel for gages usually ranges from $0.15 \%$ to $0.25 \%$. Round the answers for $\mathrm{a}$ and $\mathrm{b}$ to 2 decimal places.
a. What is the minimum weight of carbon in 250 kilograms of machine steel?
b. What is the maximum weight of carbon in 250 kilograms of machine steel?

Mohammad Mehran

Numerade Educator

01:41

Problem 24

A piece of machinery is purchased for $\$ 8792$. In 1 year, the machine depreciates $14.5 \%$. By how many dollars does the machine depreciate in 1 year? Round the answer to the nearest dollar.

Hubert Agamasu

Numerade Educator

02:25

Problem 25

. Engine pistons and cylinder heads are made of an aluminum casting alloy that contains $4 \%$ silicon, $1.5 \%$ magnesium, and $2 \%$ nickel. Round the answers to the nearest tenth kilogram.
a. How many kilograms of silicon are needed to produce 575 kilograms of alloy?
b. How many kilograms of magnesium are needed to produce 575 kilograms of alloy?
c. How many kilograms of nickel are needed to produce 575 kilograms of alloy?

Mirza Aslam Beig

Numerade Educator

01:12

Problem 26

Before starting two jobs, a shop has an inventory of eighteen 15.0 -foot lengths of flat stock. The first job requires $30 \%$ of the inventory. The second job requires $25 \%$ of the inventory remaining after the first job. How many feet of flat stock remain in inventory at the end of the second job? Round the answer to the nearest whole foot.

Nick Johnson

Numerade Educator

01:35

Problem 27

An alloy of stainless steel contains $73.6 \%$ iron, $18 \%$ chromium, $8 \%$ nickel, $0.1 \%$ carbon, and sulfur. How many pounds of sulfur are required to make 5800 pounds of stainless steel? Round the answer to the nearest whole pound.

Lottie Adams

Numerade Educator

06:06

Problem 28

Two machines together produce a total of 2015 pieces. Machine A operates for $6 \frac{1}{2}$ hours and produces an average of 170 pieces per hour. Machine $B$ operates for 7 hours. What percent of the average hourly production of Machine $A$ is the average hourly production of Machine B? Round the answer to the nearest whole percent.

Suzanne W.

Numerade Educator

Problem 1

Problem 2

Problem 3

Problem 4

Problem 5

Problem 6

Problem 7

Problem 8

Problem 9

Problem 10

Problem 11

Problem 12

Problem 13

Problem 14

Problem 15

Problem 16

Problem 18

Problem 19

Problem 20

Problem 21

Problem 22

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Problem 24

Problem 25

Problem 26

Problem 27

Problem 28