[計量] 請問印度數學11/5和11/2
印度數學11/5
4. There is a bag which consists of 10 bulbs, out of which 2 is defective. If 3 bulbs are chosen at random without replacement, then what is the probability that none of the three bulbs selected are defective?
這題有兩個答案
有兩種算法第一種是(8/10)*(7/9)*(6/8)
第2種是1-(8C3/10C3)=8/15
哪一個對...?
8. Given that there are 3 hooks and 5 pictures, find the numbers of ways to select 3 picture combinations?
(是5C3=10嗎?)
再來是11/2的印度機經
5. Given that a vending machine dispenses gumballs in a regularly repeating cycle of ten different colors. If a quarter buys 3 gumballs, what is the minimum amount of money that must be spent before three gumballs of the same color are dispensed?
(他答案是5 dollars and 1 quarter，有人知道怎麼算嗎?)
以上題目都是我不會的，要考試了，真緊張，麻煩大家了，感謝!!!
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※ 編輯: winccs 來自: 58.137.195.3 (11/10 21:56)
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