SOLUTION: 1.Some work is done by two people in 24 minutes. One of them can do this work alone in 40 minutes. How much time does the second person take to do the same work ? 2.A car is fil

Algebra ->  Rate-of-work-word-problems -> SOLUTION: 1.Some work is done by two people in 24 minutes. One of them can do this work alone in 40 minutes. How much time does the second person take to do the same work ? 2.A car is fil      Log On


   

Question 314096: 1.Some work is done by two people in 24 minutes. One of them can do this work
alone in 40 minutes. How much time does the second person take to do the same
work ?
2.A car is filled with four and half gallons of fuel for a round trip.If the
amount of fuel taken while going is 1/4 more than the amount taken for coming,
what is the amount of fuel consumed while coming back?
3.The lowest temperature in the night in a city A is 1/3 more than 1/2 the
highest during the day. Sum of the lowest temperature and the highest
temperature is 100 degrees. Then what is the low temp?

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Some work is done by two people in 24 minutes. One of them can do this work
alone in 40 minutes.
How much time does the second person take to do the same work ?
:
Let t = time for 2nd person to do the job
Let the completed job = 1
A shared work equation
24%2F40 + 24%2Ft = 1
reduce the fraction
3%2F5 + 24%2Ft = 1
multiply eq by 5t, results
3t + 5(24) = 5t
120 = 5t - 3t
120 = 2t
t = 60 min alone
:
:
2.A car is filled with four and half gallons of fuel for a round trip.
If the amount of fuel taken while going is 1/4 more than the amount taken for
coming, what is the amount of fuel consumed while coming back?
:
let x = amt of fuel consumed on the way back
then
1.25x = amt of fuel consumed going
:
x + 1.25x = 4.5
2.25x = 4.5
x = 4.5%2F2.25
x = 2 gal consumed coming back
:
:
3.The lowest temperature in the night in a city A is 1/3 more than 1/2 the
highest during the day.
L = 1%2F3H + 1%2F2H
L = 2%2F6H + 3%2F6H
L = 5%2F6H
:
Sum of the lowest temperature and the highest temperature is 100 degrees.
L + H = 100
Then what is the low temp?
:
Replace L with 5%2F6H
5%2F6H + H = 100
11%2F6H = 100
11H = 6(100)
h = 600%2F11
h = 54.54 degrees is the high
then
100 - 54.54 = 45.45 degrees is the low