Data interpretation practice
Read the table once, then apply three tools: percentage share, growth rate and ratio. Always divide by the right base: the old value for growth.
Practice table: students enrolled in a university, by faculty
| Faculty | 2022 | 2023 | 2024 |
|---|---|---|---|
| Arts | 400 | 500 | 600 |
| Science | 500 | 550 | 660 |
| Commerce | 250 | 300 | 300 |
| Education | 100 | 150 | 140 |
| Total | 1,250 | 1,500 | 1,700 |
Worked example 1: percentage share
What percentage of total enrolment in 2022 was in Science?
- Science in 2022 = 500; total in 2022 = 1,250.
- Share = 500 ÷ 1,250 × 100 = 40%.
40%
Worked example 2: growth rate
Find the percentage growth in total enrolment from 2022 to 2024.
- Increase = 1,700 − 1,250 = 450.
- Growth = 450 ÷ 1,250 × 100 = 36%.
- Check: 1,250 × 1.36 = 1,700.
36%
Worked example 3: ratio
Find the ratio of Arts to Science enrolment in 2024.
- Arts : Science = 600 : 660.
- The HCF of 600 and 660 is 60; 600 ÷ 60 = 10 and 660 ÷ 60 = 11.
10 : 11
How NET asks this: a table or chart is followed by a set of questions on percentages, ratios, averages and growth. The numbers are chosen to divide cleanly, so estimate before you calculate.
Typical MCQ: “A value rises from 250 to 300. What is the percentage increase?” (300 − 250) ÷ 250 × 100 = 20%. Divide by the old value, not the new one.
Typical MCQ: “If A : B = 2 : 3 and B : C = 4 : 5, find A : C.” Make B equal: A : B : C = 8 : 12 : 15, so A : C = 8 : 15.
Growth divides by the past; share divides by the whole. If your answer uses the new value as the base, it is the trap option.