Answer:19.1
Step-by-step explanation: Put the numbers in order and then add the numbers and then divide it by how many number there is
14+15+18+18+18+18+21+21+24+24=191
191/10=19.1
Mr. Mole's burrow was at an altitude of 6 meters below the ground.
Step-by-step explanation:
Step 1:
We need to determine the distance that Mr. Mole covers in a single minute.
To do that we divide the difference in values of altitude by the difference in the time periods.
For the first case, Mr. Mole had traveled -18 meters in 5 minutes.
We also have, he traveled -25.2 meters in 8 minutes.
Step 2:
The distance he covered in 1 minute 

So with every minute, Mr. Mole digs down an additional 2.4 meters below the surface.
To determine where Mr. Mole's burrow is we subtract the distance traveled in 5 minutes from -18.
The altitude of Mr. Mole's burrow 
So Mr. Mole's burrow was at an altitude of 6 meters below the ground i.e. -6 meters.
5 of the planets are earth like and 2 are mars like
5 * 2 = 10
<u>1 * 2 = 2</u>
Total 12
4 earth like and 4 mars like
Earth = 4*2 = 8
<u>Mars = 4 * 1 = 4</u>
Total 12
3 Like Earth 6 like mars
Earth 3 * 2 = 6
<u>Mars 6 * 1 = 6</u>
Total 12
Those answers are the only ones possible.