A husband and wife can complete a certain task in 1 and 2 hours respectively. Their children, Rae and Herman, can complete the same task in 4 and 5 hours, respectively. What is the ratio of the couple's time working together to complete the task to the children's time working together to complete the task?  Choose the correct choice from the following answers
A) a)15:46  B) b)3:10  C) c)12:23  D) d)5:18  E) e)10:3
couples one hour work=1/1+1/2=3/2   so total time=2/3..   now, kids one hour work=1/4+1/5=9/20   so total time=20/9..   ratio=2/3:20/9=3/10   ans b)3:10
<result>B</result>
A husband and wife can complete a certain task in 1 and 2 hours respectively. Their children, Rae and Herman, can complete the same task in 4 and 5 hours, respectively. What is the ratio of the couple's time working together to complete the task to the children's time working together to complete the task?