total number of students appeared should be 150...
if we consider in x and y variables, let total appeared be x, total passed be y, then totla fail wud be x-y
ratio of y to x-y is 4:1, then y=4/5x;
now if 30 less appeared, and 20 less passed, then ratio of pass to fail will be
y-20/(x-y-10)=5:1
substituting value of y, we get x= 150.
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the answer is...... by: Anonymous
consider the total no.of passed and failed students as 4x,x respectively since the ratio is 4:1.
the total no. of students appeared is,4x+x=5x.
if 30 less appeared and 20 less passed,and the ratio is 5:1,then,
5x-30/4x-20=5:1.
we get x=2.67
and 5x=13.35
and approx.13 appeared for the exam.
