Question

In a batch of 60 students, 50% of the students scored more than 80% and 70% of the students scored more than 50% in a test. 10% of the students scored less than 15 in that test. How many students scored between 15 and 60 marks if the total marks were 75?

Answer 1

From this caselet, it is important to extract the necessary data.

If the total marks were 75, 80% of that would be
$=\frac{80}{100}\times 75$
= 60

Therefore,
Number of students who scored more than 60
= 50% of 60
$=\frac{50}{100}\times 60$
= 30

So, number of students who scored less than 60 = 30

Number of students who scored less than 15
= 10% of 60
$=\frac{10}{100}\times 60$
= 6

So, number of students who scored between 15 and 60
= Total students – (Students scored more than 60 + Students scored less than 15)
= 60 – (30 + 6)
= 60 – 36
= 24