Answer:
Let's name each of the three sections of the rocket as:
- payload and navigation
- fuel
- engine
Now, we are told that:
The top section is one-sixth the length of the bottom section:
(1)
The middle section is one-half the length of the bottom section:
(2)
The total length is 240ft:
(3)
We may begin by substiting (1) and (2) in equation (3), in order to find the value of the engine section :
(4)>>>> Value of the engine section length
Then, we substitute this value of in equations (1) and (2):
(5)>>>> Value of the payload and navigation section length
(6)>>>> Value of the fuel section length