Question

In an examination,the ratio of passes to failures was 4:1 . If 30 less had appeared and 20 less passed,the ratio of passes to failres would have been5:1.How many students appeared for the examination?

Answer 1

X/Y=4/1
X=4Y

X-20/Y-10=5/1
X-20=5Y-50
X-5Y=-30

Solving
X=120,Y=30
So 150 students appeared for examination