On a survey at a particular university, 64% of the students indicated that they have misplaced their Student Identification Card at least once in the past year. If 10 students are in a campus computer lab, what is the probability that 2 or 3 of them have misplaced their Student Identification Card in the past year? Round to four decimal places, if necessary.
A) 0.6442
B) 0.0299
C) 0.1583
D) 0.0236

Question

On a survey at a particular university, 64% of the students indicated that they have misplaced their Student Identification Card at least once in the past year. If 10 students are in a campus computer lab, what is the probability that 2 or 3 of them have misplaced their Student Identification Card in the past year? Round to four decimal places, if necessary.
A) 0.6442 
B) 0.0299 
C) 0.1583 
D) 0.0236

kropot72 · Answer

$$P(2\ students)=10C2\times 0.64^{2}\times 0.36^{8}$$
$$P(3\ students)=10C3\times 0.64^{3}\times 0.36^{7}$$
When you have calculated the above two values of probability, add the two values to find the required probability.