out of some students 80% passed in maths 75% passed in English and 5% failed in both if three hundred of them passed in both subjects how many students appeared in the exam
pls give full explanation thank u☺
Answers
Answer:
Let the number of students appearing for the examination = N.
0.8*N passed in math and 0.2*N did not pass in math.
0.75*N passed in English and 0.25*N did not pass in English.
0.05*N failed both subjects.
1.) Those that passed both English and Math = (0.8)*(0.75)*N = 0.6*N.
2.) Those that passed in math and failed in English = (0.8)*(0.25)*N = 0.2*N.
3.) Those that passed in English and failed in math = (0.2)*(0.75)*N = 0.15*N.
4.) Those that failed both subjects = (0.2)*(0.25)*N = 0.05*N.
N could be any value that results in integer values for the respective percentages of N. 0.05*N limits N to 20, 40, 60, 80…,100, 120…etc.
If 100 happens to be the number of students showing up for the exams. the various numbers relative to 1, 2, 3, 4, above are:
Step-by-step explanation:
Step-by-step explanation:0.6*100 = 60.
0.2*100 = 20.
0.2*100 = 20.0.15*100 = 15.
0.2*100 = 20.0.15*100 = 15.0.05*100 = 5.