Name: Nicole
Who is asking: Student
Level: Secondary

WORKING TOGETHER ON A JOB: Patrice, by himself can paint 4 rooms in 10 hours. If he hires April to help they can do the same job together in 6 hours. If he lets April work alone , how long will it take her to paint 4 rooms?

Hi Nicole,

What you need to do is to see how many rooms Patrice alone and Patrice and April can paint in the same number of hours.

  • In 10 hours Patrice can paint 4 rooms so in 30 hours he can paint 3x4 = 12 rooms.
  • In 6 hours Patrice and April together can paint 4 rooms so in 30 hours they can paint 5x4 = 20 rooms.
(I chose 30 hours since 30 is the least common multiple of 10 and 6.)

This means that in 30 hours, April can paint 8 rooms and hence it would take her 15 hours to paint 4 rooms.

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