It take Castel 7 hours to pour a large concrete driveway. Krystal can pour the same driveway in hours. Find how long it would take them if they worked together

Question

please solve this problem with steps.

Answer 1

Maggie,

you left out the number of hours it takes Krystal.

 

However, let's pick a number and show how the

problem is worked.

If Castel takes 7 hours, Castel does 1/7 of the job per hour

If Krystal takes 9 hours, Krystal does 1/9 of the job per hour

 

(1/7 + 1/9)h = 1

(9/63 + 7/63)h = 1

(16/63)h = 1

h = 63/16

h = 3 15/16 hours

 

(15/16 hours)(60 min/hr) = 56.25 minutes

 

Together it would take them 3 hours 56.25 minutes