Asmall combination lock on a suitcase has 3 wheels, each labeled with the 10 digits from 0 to 9. if an opening combination is a particular sequence of 3 digits with no repeats, what is the probability of a person guessing the right combination?

You have to determine how many 3-digit permutations you can form using the digits from 0 to 9 with no repeats.

for the first digit you are choosing from 10 digits

for the second digit you are choosing from 9 digits

for the third digit you are choosing from 8 digits

10*9*8=720

the probability that the person guesses the correct 3-digit sequence is 1/720

Step-by-step explanation:

geometry: triangles

solvers

lessons

answers archive

call the larger triangle abc

then the smaller triangle cde is similar to abc (all angles are equal, aaa).  

ab is the side that is 36, and we wish to find de, the side corresponding to ab

area_cde = area_abc - area_cde --> area_abc / area_cde = 2

let x=length of de

ratio of areas = (ratio of sides)^2

+2+=+%2836%2fx%29%5e2+

+2+=+1296%2fx%5e2+

++x%5e2+=+1296%2f2+=+648+

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