Working together, two people can cut a large lawn in 4 hr. One person can do the job alone in 1 hr less than the other. How long would it take the faster person to do the job? the faster person would do the job alone in hours.

Question

Mathematics

Robert

12 July, 20:51

Working together, two people can cut a large lawn in 4 hr. One person can do the job alone in 1 hr less than the other. How long would it take the faster person to do the job? the faster person would do the job alone in hours.

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Answers (1)

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Trystan Bean · Answer 1

Answer:The faster person will do the job in 7.53hours

Step-by-step explanation:

Let t=faster person

Let t-1 = the other person

The job to be done = 1

Each person will do a fraction of the job

4/t+4/t-1=1

Multiply both sides wit t (t-1)

4 (t+1) + 4t=t (t-1)

4t+4+4t=t^2+t

8t+4=t^2+t

0=t^2+t-8t-4

t^2-7t-4=0

Use Almighty formular to solve d quadratic equation

X=-b + - rootb^2-4ac/2a

X=t, a=1, b=-7 c=4

Substituting the values you get:

t=-7 + - root 49+16/2

t=-7 + - root 65/2

t=7 + 8.06/2=15.06/2

t=7.53 hours