Suppose you’ve made a batch of green paint by mixing 2 cans of blue paint with 7 cans of yellow paint, but it’s run out. Your little brother, trying to be helpful sees an open can of blue paint that is ¾ full. He pours the can into a big bowl, then starts mixing in yellow paint. He pours in three cans of yellow before he brings it to you. How much paint, and of what color, would you have to add to your brother’s batch of paint to fix it so it is the exact same shade of green as your original batch?