x – .5*x + .8*x – [.75* (x – .5x +.8x)] + 2*[x – .5*x + .8*x – [.75* (x – .5x +.8x)]] – 2/3*[x – .5*x + .8*x – [.75* (x – .5x +.8x)] + 2*[x – .5*x + .8*x – [.75* (x – .5x +.8x)]]] = 39

x -.5*x + .8*x = y

y -.75*y = z

z + 2*z = a

a – 2/3*a = 39

Simplify and solve for x or use the equations on the bottom and work backwards. Easy as a piece of pie… Chocolate cream… Or the answer is 120.

Suppose: x = original number of passenger

1/3(¼+2*1/4)(X -1/2 x +4/5 x) = 39

1/3 (3/4) (13/10 x) = 39

¼ (13/10 x) = 39

13/40 x = 39

x = 120

You can check this answer by putting the answer to the story.

39 * 1.66 (0.66 being the equivilant of 2/3; if you put the 1 in front, you don’t have to add the answer to 39*0.66 to 39.) Since i’m not going to do the calculations for you, call that answer X.

take 3/4 of X, calling that answer Y. X-Y=Z.

Z*2=A.

A*4/5=B.

B/2 is your answer.

Eh, it’s been a while since i’ve done that kind of thing… My logic might be off, so double check my work, and if it makes sence, start chugging away.

If you don’t understand my logic, read your textbook very carefully. I -KNOW- it’s layed out in there somewhere, but the key is finding it. Try looking in the index or glossary; that’ll help you some.