I am not too sure about these questions.... 
Three letters are chosen at random from the word HEART and arranged in a row. Find the probability that the letter H is chosen (ANSWER: 0.6)
Three men and three women are to be randomly seated in a row. Find the probability that both the end places will be filled by women (ANSWER: 0.2)
I would appreciate any help!
b) a number of ways, i'll show you the box method for this
You have six positions, as there are six people to seat.
Here are your positions/boxes. All numbers placed in these will be multiplied.
[ ] [ ] [ ] [ ] [ ] [ ]
>> you want to find out the Probability that there is a woman on both ends.
[ 3 ] [ ] [ ] [ ] [ ] [ 2 ]
3 x 2 = 6
The first position can be occupied by 3 women (as there are only 3 women) - hence a '3' in the first box.
After the first position is occupied, there are only two women left to occupy the last position - hence a '2' in the last box.
Now that we know how many ways a woman may be in the first and last position (6 ways)
We find the TOTAL.
>>>[ 6 ] [ ] [ ] [ ] [ ] [ 5 ]
6 x 5 = 30
As there are a total of six people, any of the six can sit in the first position - hence '6' in the first box
After one of them has been chosen, any of the five can sit in the last position - hence '5' in the last box.
So the number of ways a woman can sit = 6
and the number in total = 30
6/30 = 0.2
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