Question

In an examination, the ratio of passes to failures was 4:1.Had 30 less appeared and 20 less passed, the ratio of passes to failures would have been 5:1.Find the number of students who appeared for the examination

Answer 1

Step-by-step explanation:

ratio of passes to failures was 4:1

This means if number of passed = 4a then number of failed = a

number of appeared = 4a+a = 5a

Had 30 less appeared, number of appeared would have been = 5a-30

and had 20 less passed, number of passed would have been = 4a-20

then number of failed would have been = (5a-30) - (4a-20) = 5a-30 - 4a+20 = a-10

given, the ratio of passes to failures in this case, would have been 5:1

=> (4a-20):(a-10) = 5:1

=> (4a-20)/(a-10) = 5/1

=> 4a-20 = 5(a-10)

=> 4a-20 = 5a-50

=> 5a-4a = 50-20

=> a = 30

number of appeared = 5a = 30×5 = 150