Andrew and Daniel recently took part in a marathon. After they had finished, they noticed

that Andrew finished ahead of twice as many runners as finished ahead of Daniel, and that Daniel finished ahead of 1.5 times as many runners as �finished ahead of Andrew. Andrew finished in 21st
place. How many runners took part in the marathon?

20 ahead of andrew

30 behind daniel

Now we know that

30+1+x = 2x+1+20
10=x

So, there were 41 runners, in order:

30...Daniel...10
20...Andrew...20

or, better,

20..Andrew..9..Daniel..10

A = 1 + 2x

Runners that finished ahead of Daniel is x
21 = 1 + 2x
21 - x = 2x
X = 10

Runners that finished ahead of Andrew is 20
D = 1.5 x 20
= 30 + 1
= 31
Total = 31 + 10
= 41

Let the many runners that finished ahead of Daniel be x

Andrew=1+2x
21=1+2x
21-1=2x
20=2x
x=10
Many runners ahead of Andrew are 20
Daniel =1+1.5×20
=1+30=31
Total = 31+10=
41

Ah, a classic marathon puzzler, huh? Alright, let's put on our running shoes and tackle this one!

First, we know that Andrew finished ahead of twice as many runners as finished ahead of Daniel. So, if we let "x" represent the number of runners ahead of Daniel, that means there were 2x runners ahead of Andrew.

Now, we also know that Daniel finished ahead of 1.5 times as many runners as finished ahead of Andrew. So, there were 1.5 times 21 runners, or 31.5 runners, ahead of Daniel.

Well, it seems like we can't have half a runner, can we? So let's round that up and get 32 runners ahead of Daniel.

Now, if there were 2x runners ahead of Andrew, and we know there were 32 runners ahead of Daniel, we can set up an equation:

2x = 32

Solving for x, we find that there were 16 runners ahead of Daniel.

Since Andrew finished in 21st place, that means there were 20 runners between him and the finish line. And if there were 16 runners ahead of Daniel, that means there were 15 runners between him and the finish line.

Adding them all up, we have:

20 (runners ahead of Andrew) + 15 (runners ahead of Daniel) + 2 (Andrew and Daniel themselves) = 37 runners

So, it looks like a grand total of 37 runners took part in the marathon! Phew, that was a bit of a clown dance, but we got there in the end!

To solve this problem, we can use a system of equations. Let's denote the number of runners as "x".

According to the information given, Andrew finished ahead of twice as many runners as finished ahead of Daniel. This means that if Andrew finished in 21st place, then there were 20 runners ahead of him (since Andrew is in 21st place, there are 20 runners ahead of him). Therefore, there were 2 * 20 = 40 runners who finished behind Andrew and ahead of Daniel.

The second piece of information tells us that Daniel finished ahead of 1.5 times as many runners as finished ahead of Andrew. From the above calculation, we know that there were 20 runners who finished ahead of Andrew. Therefore, there were 1.5 * 20 = 30 runners who finished behind Daniel and ahead of Andrew.

Now, let's calculate the total number of runners:
- There are 20 runners ahead of Andrew
- There are 30 runners ahead of Daniel
- Andrew and Daniel both finished, so that accounts for 2 more runners

The total is: 20 + 30 + 2 = 52 runners.

So, there were 52 runners who took part in the marathon.