X equals to 48
The work is shown in the picture. I hope this helps.
Answer:
60 students passed, and 75 appeared in examination.
Step-by-step explanation:
Let's say s is the total number of students and p is the number of students who passed.
80% of the students passed, so:
0.8 s = p
If there were 10 less passers, and 15 less students (5 less failures), then the ratio of passers to failures would be 5/1.
(p − 10) / (s − p − 5) = 5 / 1
Simplify the second equation:
p − 10 = 5 (s − p − 5)
p − 10 = 5s − 5p − 25
6p = 5s − 15
Substitute the first equation.
6 (0.8 s) = 5s − 15
4.8 s = 5s − 15
0.2 s = 15
s = 75
p = 0.8 s
p = 60
60 students passed, and 75 appeared in examination.
The probability he will select a hockey card is 1/4, and then the probability that he selects a baseball card without replacement is 1/6.
Primary sources contain information
A. with the advantage of hindsight and the perspective of an outside observer and may be more objective.
B. provided by someone who's been through an event. It's a firsthand account that lends a unique perspective.
C. on statistics gathered after an important historical event.
D. on psychological information gathered from raw data from psychological tests.