Number one is c. It should take her about nine days
If this is in science terms its a plain if this is in mathematical terms, the answer is the number 0 anything below is negative, anything abouve is pos
To answer this question, use permutation since the order of the letter matters. There are 7 letters and only 4 are to be used for the code. This is a permutation of 7 taken 4 (7P4) which is equal to 840. Thus, the sample space is 840.
For the next questions, there are 3 vowels for as the first letter, only 6 letters are available for the second, 5 on the next, and 4 on the last. Multiplying these numbers give 360. To solve for probability, divide this number with the sample space. Thus, the answer is 3/7.
