Working alone, Jamie can mow her lawn in 75 minutes. If Bob helps her, then the two can mow the lawn in 30 minutes. How long does it take Bob to mow the lawn alone? Pls give explanation

20 POINTS + BRAINLIEST

9514 1404 393

  50 minutes

Step-by-step explanation:

"Working together" problems like this usually give you the time per task. However, the rates of getting work done add when expressed as tasks per time.

Let b represent the number of minutes Bob takes to mow the lawn alone. Then the sum of lawns mowed per minute is ...

  Jamie's rate + Bob's rate = "working together" rate

  1/75 + 1/b = 1/30

  1/b = 1/30 -1/75

  1/b = 5/150 -2/150 = 3/150

  1/b = 1/50

  b = 50

It takes Bob 50 minutes to mow the lawn alone.

step-by-step explanation:

given that there are two triangles j'k'l' and jkl>

the former is got by dilating the second one.

when drawn on a grid, (graph paper) coordinates of vertices of first triangle is

(6,12)j, (9,6)k and (12,9)l

side jk has length = distance between j and k

=

side j'k'=distance between j' and k'

=

ie j'k'l' has sides 1/3 of that of corresponding sides of jkl.

hence scale factor of 1/3 is used to get j'k'l'from jkl