Is the angular speed of the hour hand of a clock greater than, less than, or equal to the angular speed of the minute hand?

350 white copies and 50 coloured copies

Step-by-step explanation:

$0.10 per coloured copy (c)

$0.05 per white copy (w)

$22.50 total bill

c = number of coloured copies

w = number of white copies

400 = number of total copies

Write a system of equations:

c + w = 400; c = 400 – w

0.1c + 0.05w = 22.5

Replace one variable in the more complex equation:

0.1(400 – w) + 0.05w = 22.5

Solve:

0.1(400 – w) + 0.05w = 22.5

40 – 0.1w + 0.05w = 22.5

40 – 0.05w = 22.5

–0.05w = 22.5 – 40

–0.05w = –17.5

w = –17.5 ÷ –0.05

w = 350

c = 400 – w

c = 400 – 116.7

c = 50