<PRE><B>Question 1020945</B>
1) let x be total marbles in the box, then
0.35 * x = 7
x = 7 / 0.35 = 20
There are 20 marbles in the box
7 + 9 + r = 20 where r is the number of red marbles
*****************************************************
therefore there are 4 red marbles added to the box
*****************************************************
2) you would have to draw 18 marbles to be sure you get two of each color
:
: reasoning is you could draw all the green and blue marbles before drawing 2 red marbles, therefore to be sure 7 + 9 + 2 = 18

</PRE>