SOLUTION: a box contains orange, purple and black marbles. Of the total, 1/3 are orange, 1/5 are purple and the remaining 77 marbles are black. How many marbles are in the box?

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: a box contains orange, purple and black marbles. Of the total, 1/3 are orange, 1/5 are purple and the remaining 77 marbles are black. How many marbles are in the box?      Log On


   

Question 592566: a box contains orange, purple and black marbles. Of the total, 1/3 are orange, 1/5 are purple and the remaining 77 marbles are black. How many marbles are in the box?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
a box contains orange, purple and black marbles. Of the total, 1/3 are orange, 1/5 are purple and the remaining 77 marbles are black. How many marbles are in the box?
----------------------
Let total # of marbles be "x":
Equation:
(1/3)x + (1/5)x + 77 = x
-----
(8/15)x + 77 = x
(7/15)x = 77
x = 11*15
x = 165 (total # of marbles)
=================================
Cheers,
Stan H.
=====================