Question

44. David and Michael together can finish a job in4 days 19 hrs 12 min. If David works at two-thirdsMichael's speed, how long does it take Michaelalone to finish the same job?​

Answer 1

Answer:

The work done by Michael alone to finish same job is in 12 days .

Step-by-step explanation:

The work finished by David and Michael working together in = 4 days 19 h 12 min

i.e The work finished by David and Michael working together in = 6912 minutes

Now, David works at two-thirds Michael's speed,

Let The work done by Michael alone in = x minutes

So, The work done by David alone in = $\dfrac{2 x}{3}$ minutes

According to question

The work finished by David and Michael working together in = The work done by Michael alone in + The work done by David alone in

I.e $\dfrac{1}{6912}$ = $\dfrac{1}{x}$ + $\dfrac{1}{\frac{2x}{3}}$

Or, $\dfrac{1}{6912}$ = $\dfrac{1}{x}$  + $\dfrac{3}{2 x}$

Or, $\dfrac{1}{6912}$ = $\dfrac{2 + 3}{2 x}$

Or, $\dfrac{1}{6912}$ = $\dfrac{5}{2 x}$

Or, 2 x = 5 × 6912

∴  x = 17,280 minutes

Or, x = 12 days

So, The work done by Michael alone in = x = 17,280 minutes

i.e The work done by Michael alone in = x = 12 days

Hence, The work done by Michael alone to finish same job is in 12 days . Answer

Answer 2

Answer:

MICHAEL COMPLETE THE WORK IN 8 DAYS

Step-by-step explanation:

D+M = 4days 19hr 12min

=4 days 19hrs 12/60

= 4days 19hrs 1/5

= 4days 19+ 1/5= 96/5

{1days =24 hours = 1/24 hrs}

= 4days 96/5×1/24 = 4/5 days

= 4 + 4 = 24

5 5

devid and Michael together 1 day work =5

24

RATIO IS - D:M

2:3

MICHAEL = 5 × 3

24 5

= 1

8 = 8days

MY DEAR FRIENDS ANS IS "8" DAYS