SOLUTION: A bucket is full of red marbles and white marbles. There are twice as many white marbles as red ones. If I add seven white marbles, there will be three times as many white marbles

Question 795432: A bucket is full of red marbles and white marbles. There are twice as many white marbles as red ones. If I add seven white marbles, there will be three times as many white marbles as red ones. How many marbles were in the bucket before the white marbles were added?
Answer by josgarithmetic(39620) (Show Source): You can put this solution on YOUR website!
r for count of red marbles
w for count of white marbles

, and , translated from the description.
You can continue is these make sense; or study and think carefully if they do not make sense.

A change is described for the white marble count which is hypothetical, while no change to the value of the red marble count would happen.

.
.
If you feel good about the system, then simply substitute for w into the plus-seven equation, and solve first for r.
...
RELATED QUESTIONS
A jar has twice as many red marbles as white marbles and the ratio of blue marbles to... (answered by Boreal)

A jar has twice as many red marbles as white marbles and the ratio of blue marbles to... (answered by scott8148,stanbon)

Hi There were 350 marbles in a box. 40% of them are red. There were 10% more red... (answered by math_helper)

A bag contains red, white, green, and blue marbles. There are an equal number of red... (answered by ikleyn,greenestamps)

hI! please help me with this There are two jars each containing red and white... (answered by checkley71)

(a) A box contains red and white marbles. The total number of marbles is 265. The... (answered by checkley79)

Two identical jars are filled with equal marbles. The marbles are colored red or white. (answered by scott8148)

Hi there were 350 marbles in a box. 40% of them were red.there were 10% more red than... (answered by greenestamps)

there are 16 red marbles and 48 white marbles. what is the probability of randomly... (answered by checkley79)