SOLUTION: Bobby has a bag containing two sizes of marbles. The big ones weigh 8 g and the small ones weigh 2 g. If there are twice as many small ones as big ones and the bag weighs 324 g, ho
Question 156173: Bobby has a bag containing two sizes of marbles. The big ones weigh 8 g and the small ones weigh 2 g. If there are twice as many small ones as big ones and the bag weighs 324 g, how many big marbles does he have? Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! The big ones weigh 8 g and the small ones weigh 2 g. If there are twice as many small ones as big ones and the bag weighs 324 g, how many big marbles does he have?
:
Let x = no. of big ones
and
Let y = no. of small ones
;
Write an equation for the total weight
8x + 2y = 324
:
Write an equation for the statement:
"there are twice as many small ones as big ones"
y = 2x
;
Substitute 2x for y in the total weight equation, find x:
8x + 2(2x) = 324
:
8x + 4x = 324
:
12x = 324
x =
x = 27 big ones
then
y = 2(27)
y = 54 small ones
:
:
Check solution in the total weight equation:
8(27) + 2(54) =
216 + 108 = 324
