Help with permutations (no links or files) How many ways can 3 different books, 5 chemistry books, and 7 physics books be arranged on a shelf if the books of each subject must be kept together?

6.5

step-by-step explanation:

you said it was in the question

~courtney

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4

n word

step-by-step explanation:

what lives in the hood