rational equation

Question

Jordan can build a birdhouse in 2 hours. If it takes her sister 3 hours to build a birdhouse, how long will it take them to build a birdhouse together?

Answer 1

time together + time together = 1

   time alone          time alone

 

t/2 + t/3 = 1       Multiply both sides by 6.

3t + 2t = 6

5t = 6

t = 1 1/5 hours