Question

The pie diagram in figure shows the proportions of different workers in a town. Answer the following questions with its help.
(1) If the total workers is 10,000; how many of them are in the field of construction ?
(2) How many workers are working in the administration ?
(3) What is the percentage of workers in production ?

Answer 1

(1)
Number of workers working in the field of construction$=\frac{\mathrm{central}\mathrm{angle}\mathrm{for}\mathrm{construction}}{360°}\times 10000$
$=\frac{72°}{360°}\times 10000$
​= 2000

(2)
Number of workers working in the administration$=\frac{\mathrm{central}\mathrm{angle}\mathrm{for}\mathrm{administration}}{360°}\times 10000$
$=\frac{36°}{360°}\times 10000$​
= 1000
​
(3)
Percentage of workers working in production$=\frac{\mathrm{central}\mathrm{angle}\mathrm{for}\mathrm{production}}{360°}\times 100\%$
$=\frac{90°}{360°}\times 100\%$​
= 25%