= (x^18y^24)/(x^2y^2)
Simplified = x^16y^22
The last answer is correct (x^16y^22)
35-15 is 20. and 43-26 is 17. These two are different because you are regrouping in the 2d problem, as in the first, you just subtract.
For each coin, there are <u>2 outcomes</u>, heads (H) or tails (T), so for the <u>3 coins</u>, the number of outcomes are:
2 x 2 x 2 = <u>8 outcomes:</u>
HHH / HHT / HTH / THH / TTT / TTH / THT / HTT
Out of all these outcomes, there are <u>3 ways</u>, we get exactly 2 Heads:
HHT / HTH / THH
So, the probability of exactly 2 coins landing on Heads is 3/8, or 0.375
