Answer:
Let x be the number of left handed female students and let y be the number of left handed male students.
Then the number of right handed female students will be 5x and the number of right handed male students will be 9y. Since the total number of left handed students is 18 and the total number of right handed students is 122, the following system of equations must be satisfied.
x+y=18 and 5x+9y=122
Solving this system gives x=10 and y=8.
Thus, 50 of the 122 right handed students are female. Therefore, the probability that a right handed student selected at random is female is the fraction 50/122
which to the nearest thousandth is 0.410.
T is average time spend by shoppers in minutes
N average number of shoppers.
Here, shoppers/hour =84.
Hence r=
60
84
T=5
Hence N=rT=
60
84
×5=7
Average number of shoppers waiting at checkout =7
