from parade magazine, august 3,1997, page 8 by marilyn vass savant, can you help with this poblem? suppose it takes one man 5 hours to paint a house and it takes another man 3 hours to paint the same house. if the two men work together, how many hours would it take them? calculate the answer.

Question

anonymous · Answer

heck no

anonymous · Answer

answer is 
$$\frac{5\times 3}{5+3}$$

anonymous · Answer

you need method or just the answer? it should be clear how i used the numbers and it is a very general solution
if one man paint the house in $x$ hours and the other in $y$ hours then working together they will paint it in $\frac{xy}{x+y}$ hours

radar · Answer

Unless they are painting overlapping areas lol

radar · Answer

by the way I like that product over sum, it works for parallel connected resistors when calculating total resistance.

anonymous · Answer

thank you satellite 73:)

anonymous · Answer

yw

anonymous · Answer

@radar really?

radar · Answer

Yes, if there is more than two, you work them two at a time.

anonymous · Answer

oh! learn something new every day