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) (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(52921) (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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