In a “Relay for Life” event, the combined distance covered by Fred, Sam & Joe is 4000 metres. If Fred ran twice as far as Sam and Joe ran 500 metres less than Sam, how far did each
competitor run??

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

answer: 80,000

step-by-step explanation:

the population doubles every day.

10,000*2=20,000 day 4

20,000*2=40,000 day 5

40,000*2=80,000 day 6

2 apples

step-by-step explanation:

taking away equals subtraction. 6-4=2