Answer:
In B, One card is chosen from a standard deck, it is set aside, then a second card is drawn. That "set aside" is where we have a problem. We began with 52 cards, but now have 51. This fact WILL change the probability or probabilities. Chances of obtaining a red heart from the full 52-card deck are 4/52; whereas chances of obtaining a red heart from the remaining 51 cards (assuming that you got a red heart earlier and set it aside) is 3/51.
% of decrease would be 100 - (22*100)/28
=100-78.57 = 21.43%
They are adjacent angles, they don't overlap and share a common vertex.
5x630=3150. 3150-2910=240. 240/3=80. There were 80 kids.
