Question

Six students take an exam two times. The increase in average marks of all the students
from first test to second test is 30%.The difference of the total marks of first five
students in the two tests is 20% of their total marks in second test. If in the first test
the marks of the sixth student were mistakenly written 1/9 times more than the
original, what is the actual percentage increase in his marks?

Answer 1

We can create the equation:

0.3(180) + (n/100)(150) ≥ 0.5(330)

54 + 3n/2 ≥ 165

3n/2 ≥ 111

3n ≥ 222

n ≥ 74