Goodevening.

Christopher can paint the interior of his house in 30 hours. If he hires Cynthia to help him they can do the same job together in 18 hours. If he lets Cynthia work alone, how long will it take her to paint the interior of his house?

Enter the exact answer.

Cynthia can paint the house alone in_________hours.

Question

Goodevening.

Christopher can paint the interior of his house in 30 hours. If he hires Cynthia to help him they can do the same job together in 18 hours. If he lets Cynthia work alone, how long will it take her to paint the interior of his house?

Enter the exact answer.

Cynthia can paint the house alone in_________hours.

amistre64 · Answer

how much of the house can chris paint in an hour?

amistre64 · Answer

if 30 hours equals 1 house , then divide each by 30 to get 1 hour

then 30/30 hours equals 1/30 house;  Chris can finish 1/30 in an hour

we dont know how much the girl can do so leave it unknown;  1/C

add them up to get get 1/18 of the house in an hour to find C

anonymous · Answer

ist 45? thank u @amistre64  =)

amistre64 · Answer

youre welcome, these used to, and sometimes still, confuse me ;)  good luck