SOLUTION: I'm helping to teach some Soldiers in math when I came across a question that stumped me. I'm hoping you can help out.
If 2 boys can build 6 sandcastles in 3 and 1/3 hours, how
Algebra ->
Rate-of-work-word-problems
-> SOLUTION: I'm helping to teach some Soldiers in math when I came across a question that stumped me. I'm hoping you can help out.
If 2 boys can build 6 sandcastles in 3 and 1/3 hours, how
Log On
Question 498927: I'm helping to teach some Soldiers in math when I came across a question that stumped me. I'm hoping you can help out.
If 2 boys can build 6 sandcastles in 3 and 1/3 hours, how long will it take for 3 boys to build 11 sandcastles?
Thanks in advance! Found 2 solutions by Alan3354, Edwin McCravy:Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website! If 2 boys can build 6 sandcastles in 3 and 1/3 hours, how long will it take for 3 boys to build 11 sandcastles?
------------------
2 boys * 3 1/3 hrs = 20/3 boy-hrs to build 6
--> 10/9 boy-hrs per castle
--------------
11 castles --> 110/9 boy-hrs
(110/9) boy-hrs/3 boys = 110/27 hours
=~ 4.074 hours
You can put this solution on YOUR website! If 2 boys can build 6 sandcastles in 3 and 1/3 hours, how long will it take for 3 boys to build 11 sandcastles?
Thanks in advance!
The easiest way to do job-worker-time problems is to use the formula:
where
W1 = the number of workers in the first situation.
T1 = the number of time units (hours in this case) in the first situation.
J1 = the number of jobs in the first situation.
W2 = the number of workers in the second situation.
T2 = the number of time units (hours in this case) in the second situation.
J2 = the number of jobs in the second situation.
W1 = 2 W2 = 3
T1 = T2 = the unknown quantity
J1 = 6 J2 = 11
Substituting:
Multiply both sides by the LCD of 66 to clear of fractions:
Change to , Multtiply 6×3 on the right
Multiply both sides by 3
Answer: hours, or about 4 hours and 4.4 minutes.
Edwin
