Question

In an examination, 40% of students passed in Maths only, 30% passed in Science only and 10% students failed in both subjects. If 200 students passed in science, find the total number of students by drawing Venn-diagram.​

Answer 1

• 400 students

Explanation:

Given:

• 40% of students passed in Maths only
• 30% passed in Science only
• 10% students failed in both subjects
• 200 students passed in science

Let the total number of students is x.

Then the number of students passed in both subjects is:

• x - (0.4x + 0.3x + 0.1x) =
• x - 0.8x =
• 0.2x

Number of students passed in science is:

• 0.3x + 0.2x = 200
• 0.5x = 200
• x = 200/0.5
• x = 400

Venn diagram looks like below.

Consider 'Math' and 'Science' as two circles, 'Both' is the intersection of circles, 'Neither' is outside of the two circles.

• Math Both Science Neither
• 40% 20% 30% 10%