Answer:
Stephen has 9 trees
Alice has 21 trees
Step-by-step explanation:
<u>At the beginning:</u>
Stephen = x trees
Alice = x + 12 trees
<u>At the end:</u>
Alice = (x + 12) - 4 trees
Stephen = x + 10 trees
Total = 36
Then

Stephen - 9 trees
Alice - 9 + 12 = 21 trees
<span> 63 in four different ways
1) 63 ones
2) 6 tens and 3 ones
3) 3 tens and 33 ones
4) 4 tens and 23 ones</span>
Eric took 20 hours to do the job alone.
<u>Step-by-step explanation</u>:
<u>Given </u>:
- Total work = 75 packages
- Joe took 5 hours to complete the total work.
The amount of work Joe alone can do per hour = 75/5 = 15 packages.
The amount of work Joe and Eric together do per hour = 75/4 = 18.75
The amount of work Eric alone can do per hour = 18.75 - 15 = 3.75
The time Eric took to complete the entire work = 75 / 3.75 = 20 hours.