Arthur is organising hi collection of DVDs. He has 98 altogether. The ratio of comedy films to action to horror is 4:7:3... How many of each type of DVD does he have?

Question

anonymous · Answer

help please

mathmale · Answer

Welcome to OpenStudy!  

Have you worked with ratio problems before?

Supposing you had 14 books, and that among them you had 4 comedy films, 7 action films and 3 horror films.  The ratio "commedy" to "action" to "horror" is 4:7:3, as you might expect.  Now suppose you had 28 books (which is 2 times 14 books); if their distribution followed the same ratio, you'd now have 8 comedy, 14 action and 6 horror films.  Notice the 8:14:6 = 4:7:3.  

Finally, supposing you had 98 books (as you do in this problem), and that their types still have the ratio 4:7:3.  How many of each kind of book have you?

In my example, I just multiplied 4, 7 and 3 by 2.  Now, in this problem, just multiply 4, 7 and 3 by x, which is unknown, and find x.

Hint:  4x + 7x + 3x = 98

anonymous · Answer

so I just multiply them all by 3?