Basic Technical Mathematics, 11th Edition

CHAPTER 18 REVIEW EXERCISES

CONCEPT CHECK EXERCISES

Determine each of the following as being either true or false. If it is false, explain why.

1. The ratio of 25 cm to 50 mm is 5.

2. If 20 m is divided into two parts in the ratio of 3/2, the parts are 14 m and 6 m.

3. If y varies inversely as the square of x, and $y\hspace{0.17em}=\hspace{0.17em}4$ when $x\hspace{0.17em}=\hspace{0.17em}\mathrm{1/4}\hspace{0.17em},\hspace{0.17em}$ then $y\hspace{0.17em}=\hspace{0.17em}4\hspace{0.17em}/\hspace{0.17em}{x}^2\hspace{0.17em}.\hspace{0.17em}$

4. If R varies jointly with s and the square of t, and inversely as the square of r, then $k\hspace{0.17em}=\hspace{0.17em}\left({\displaystyle \frac{R}{s}}\right){\left({\displaystyle \frac{r}{t}}\right)}^2\hspace{0.17em}.\hspace{0.17em}$

PRACTICE AND APPLICATIONS

In Exercises 5–18, find the indicated ratios.

5. 840 mg to 3g

6. 300 nm to $6\mu \text{m}$

7. 375 mL to 25 cL

8. 12 ks to 2 h

9. The number $\pi$ equals the ratio of the circumference c of a circle to its diameter d. To check the value of $\pi \hspace{0.17em},\hspace{0.17em}$ a technician used computer simulation to measure the circumference ...