X = short section of rope
4x = longer section of rope
x + 4x = 25
5x = 25
x = 5
…or in other words the shorter piece of rope is 5 feet long
Answer:
40/9
Step-by-step explanation:
Use the work formula,
+
=
, where A is the amount of time it takes one person, B is the amount of time it takes another person, and T is the time it takes for them to work together.
Plug in the times for David and Alex alone:
+
= 
Find the least common denominator, which is 40.
+
= 
= 
Cross multiply and solve for T:
9T = 40
T = 40/9
So, if they worked together, it would take them 40/9 hours
Question 3:
If the diver is being pulled up at 25 feet every minute, in 10 minutes they would have been pulled up 10 times that
10*25=250
The diver is now 200 feet below, but 10 minutes ago they would have been 250 feet deeper so:
200+250=450
450 feet
Two hundred eighty one million four hundred eighty thousand one hundred