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20 votes
There were three parts to Rita's race. She ran the first part, which was 4/9

of the total distance, in 20 minutes. She ran the second part, which was 2/5
of the remaining distance, in 12 minutes. She finally ran the third part in 15 minutes at a speed of 300 meter per minute.
A) How long was the first part of the race? What was Rita's speed in that section of the race?
B)How long was the second part of the race? What was Rita's speed in that section of the race?

User HGPB
by
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1 Answer

11 votes

Answer:

300 meters per minute

Explanation:

Step 1

Determine the fraction of the total distance for each part of the race.

Given:

1st part of race = 4/9 of total distance

2nd part of race = 2/5 of remaining distance

Step 2

Determine the distance of the third part of the race.

Given:

time = 15 minutes

speed = 300 meters per minute

Step 3

If the third part of the race (which is 1/3 of the total distance) is 4500m, then the distance of the whole race is:

Step 4

Determine the distance of the 1st part of the race:

Step 5

Determine the speed of the 1st part of the race:

Given:

time = 20 minutes

distance = 6000 m

User Sudcha
by
3.5k points