Answer:
Step-by-step explanation:
Use order of operations (PEMDAS)
<span>83-<span>(<span>59-<span>(<span>22-18</span>)</span></span>)
</span></span><span><span>83-<span>(<span>59-4</span>)
</span></span></span><span><span>83-55=</span></span>28
Final answer: 28
<h3>Answer:</h3>
2/15
<h3>Explanation:</h3>
There are 8C2 = 28 ways to choose 2 dimes from the 8 dimes in Annie's purse. There are 21C2 = 210 ways to choose 2 coins from the 21 coins in Annie's purse.
Of the 210 ways to choose 2 coins, 28 of the choices will result in 2 dimes being chosen. The probability of choosing 2 dimes is 28/210 = 2/15.
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<em>Comment on nCk</em>
The number of ways to choose k objects from n, when order does not matter, is ...
... n!/(k!(n -k)!)
For the computations above, we have ...
... 8C2 = 8·7/(2·1) = 28
... 21C2 = 21·20/(2·1) = 210
Is that all the info ? If so say 128 voted
Answer:
7
Step-by-step explanation:
Since the goal is to draw three marbles of the same colour, regardless of which colour that is, the worst possible scenario would be drawing two marbles of each color in the first six picks (2 red, 2 white and 2 blue). At this point, with the 7th pick, no matter what colour marble the student picks will form three of the same kind.
Therefore, the minimum number of marbles which students should take from the box to ensure that at least three of them are of the same colour is 7.
