I hate problem solving!!! pls help!

1. The OfficeJet printer can copy Janet's dissertation in 20 mins. The LaserJet printer can copy the same document in 8 mins. If the two machines work together, how long would they take to copy the dissertation? simplify answer and pls show work.

2. A long distance trucker traveled 72 miles in one direction during a snow storm. The return trip in rainy weather was accomplished at double the speed and took 2 hours less time. Find the speed going. Pls show work?

3. Joe's tractor is just as fast as Gail's. It takes Joe 2 hours more than it takes Gail to drive to town. If Joe is 104 miles from town and Gail is 78 miles from town, how long does it take Gail to drive to town? Pls show work?

4. There are approximately 5 lbs of muscle for every 6 lbs of body weight of a certain animal. For a 126-lb animal, how much of the weight is muscle? pls show work,

5. 10cm^3 of a normal specimen of human blood contains 1.2 g of hemoglobin. How many grams does 12 cm^3 of the same blood contain? pls show work.

Thanks so much? I really can't stand problem solving!!! lol.

1. Rate of officejet = 1/20
Rate of Laserjet = 1/8

Combined rate of work = 1/20 + 1/8

Time taken = 40/7 minutes

2. Let x be speed of truck; h be original hours taken.

x * h = 72 (in the snow) ------------- (1)

On return trip speed becomes 2x, and time becomes h-2

2x * (h - 2) = 72

Or x * (h - 2) = 36

Or x * h - 2x = 36

Substituting x*h = 72 from (1) and solving for x

x = 18 miles per hour

3. Similar to the above problem.

For Joe x * (h+2) = 104

For Gail x * h = 78

Solving, you get x = 13 miles/hour

and time for Gail = 6 hrs

4. 5 lbs muscle for 6 lbs body weight

or 6 lbs body weight has 5 lbs muscle

so 126 lbs body weight has 126 * 5 / 6 = 105 lbs of muscle

5. 10 cc blood has 1.2 g hemoglobin

so 12 cc blood has 12 * 1.2 / 10 = 1.44 g hemoglobin

And I hate people that post their homework papers for us to do so they can get credit for it.