Question 766221

I'm confused with this equation here:

[(r+2)/(20)]*[(5)/(12r+24)] It's written out as fractions, but I don't know how to do that on here. 

The book says the answer is 1/48, but I'm a little confused by how it came to that conclusion. Can someone show me how?


{{{((r + 2)/20) * ((5)/(12r + 24))}}} ------ {{{((r + 2)/20) * ((5)/(12(r + 2)))}}} ------ {{{(cross((r + 2))/4cross(20)) * (cross((5))/(12cross((r + 2))))}}} ------- {{{highlight_green(1/48)}}}