SOLUTION: Can you please help me solver this word problem: Eric can defeat 3 soldiers in 10 minutes while Tobias can defeat 5 soldiers in 6 minutes. If there are 30 soldiers guarding the

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Question 888384: Can you please help me solver this word problem:
Eric can defeat 3 soldiers in 10 minutes while Tobias can defeat 5 soldiers in 6 minutes. If there are 30 soldiers guarding the headquarters, how long will Eric and Tobias fight together to defeat the soldiers if Eric starts fighting alone and then Tobias joins him 1 minute later? (State Exact answer as well as rounded to one decimal place)

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Eric's rate of defeating soldiers is:
( 3 soldiers / 10 min ) = ( 3/10 soldiers / 1 min )
After 1 minute, there are +30+-+3%2F10+=+297%2F10+ soldiers left
Add their rate of defeating soldiers and
let +t+ = time in hours to defeat remaining soldiers
+3%2F10+%2B+5%2F6+=+%28+297%2F10+%29+%2F+t+
+3%2F10+%2B+5%2F6+=+297%2F+%28+10t+%29+
Multiply both sides by +30t+
+9t+%2B+25t+=+3%2A297+
+34t+=+891+
+t+=+26.206+
+.206%2A60+=+12.36+
---------------------
Fighting together, it takes them 26 min 12 sec to
finish defeating soldiers
----------------------
check:
+3%2F10+%2B+5%2F6+=+297%2F+%28+10t+%29+
+3%2F10+%2B+5%2F6+=+297%2F+%28+10%2A26.206%29+
+.3+%2B+.8333+=+296+%2F+262.06+
+1.1333+=+1.1295+
close enough