1)Sheyna drive to the lake and back. It took two hours less time to get there than it did to get back. The average speed on the trip there was 60 mph. The average speed on the way back was 36 mph. How many hours did the trip there take?

8 hours

Step-by-step explanation:

Given:

Sheyna drives to the lake with average speed of 60 mph and

Sheyna drives back from the lake with average speed of 36 mph

It took 2 hours less time to get there than it did to get back.

Let be the time taken to drive to lake.

Let be the time taken to drive back from lake.

hrs ..... (1)

To find:

Total time taken = ?

Solution:

Let D be the distance to lake.

Formula for time is given as:

Putting in equation (1):

So,

So, the answer is:

x = 25/2304

step-by-step explanation:

7 weeks

step-by-step explanation:

convert each fraction to the least common multiple of 20, so 3/4 = 15/20 & 1/10 = 2/20, then divide 15 by 2 and you get a little over 7, so the food will last 7 weeks.