Jon has 2 boxes, A & B. In Box A, there are 470 yellow M& M's and 480 orange M$ M's. In the Box B, 350 yellow M& M's and 200 oranges M& M's. Some M & M's are transferred from the Box B to Box A. As a result 60% of the M & M's in the Box A and 20% of the M & M's in Box B are yellow. How many yellow and orange M & M's are transferred from Box B to Box A?
A - 470 Y, 480 O
B - 350 Y, 200 O
So let's say after transferring the M&M's, box B has b yellow ones. That means box B also has 4b orange ones (because 0.8 = 4 times of 0.2). Meanwhile, box A will have a yellow M&M's and 2a/3 orange ones.
We have 820 yellow ones total and 680 orange ones total.
a + b = 820
2/3*a + 4b = 680
We can multiply the first equation by 4 to get 4a + 4b = 3280. Now subtract the second equation from this, and we find that 10/3*a = 2600. So a = 780.
So box A now has 780 yellow ones and 520 orange ones.
Subtracting, we find that 310 yellow M&M's and 40 orange M&M's were moved.