SOLUTION: need to write an equation and solve The main engine of a rocket fired alone can burn all the fuel in 50 seconds. The secondary engine fired alone can burn all the fuel in 80 sec

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Question 1013788: need to write an equation and solve
The main engine of a rocket fired alone can burn all the fuel in 50 seconds. The secondary engine fired alone can burn all the fuel in 80 seconds. How long can both engines be fired together before all the fuel is consumed?

Found 2 solutions by solver91311, ikleyn:
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


The main rocket burns all of the fuel in 50 seconds, so it must burn of the fuel in one second. Likewise, the secondary rocket burns of the fuel in one second. Together they burn of the fuel in one second. Therefore, together they burn all of the fuel in seconds. Just do the arithmetic. Correct arithmetic gets you an answer greater than 29 seconds but less than 32 seconds.

John

My calculator said it, I believe it, that settles it

Answer by ikleyn(52920) About Me  (Show Source):
You can put this solution on YOUR website!
.
The main engine of a rocket fired alone can burn all the fuel in 50 seconds. The secondary engine fired alone can burn all the fuel in 80 seconds.
How long can both engines be fired together before all the fuel is consumed?
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