Stan and Hilda can mow the lawn in 50 min if they work together. If Hilda works twice as fast as Stan, how long does it take Stan to mow the lawn alone?

Question

 modeling w/ equations.

Answer 1

Hi Samantha,

Let  t = Time it takes Stan's to mow the lawn, then Hilda will take = t/2

Rate of Work X Time = 1

stan's rate of work   = 1/t

Hilda's rate of work  = 2/t

(Stan's rate of work)X50min + (Hilda's rate of work)X50 min = 1

(1/t)X50 + (2/t)X50 = 1

50/t + 100/t = 1

150/t = 1

t = 150 minutes

Stan will take 150 minutes  or 2.5 hours to mow the lawn by himself.

Answer 2

So, if Hilda works twice as fast as Stan, Stan only does a third of the work in 50 minutes, so how long will it take him to do the entire lawn alone if 50 minutes only covers one-third of the work?