GATE CS 2024 Set 2 Q.8: Data Interpretation and Graphs

The pie charts depict the shares of various power generation technologies in the total electricity generation of a country for the years 2007 and 2023.

Two pie charts comparing electricity generation shares in Year 2007 (Coal 35%, Gas 25%, Hydro 30%, Wind 5%, Solar 5%) and Year 2023 (Coal 20%, Gas 15%, Wind 10%, Hydro 35%, Solar 20%).

The renewable sources of electricity generation consist of Hydro, Solar and Wind. Assuming that the total electricity generated remains the same from 2007 to 2023, what is the percentage increase in the share of the renewable sources of electricity generation over this period?

25%

50%

77.5%

62.5%

Official answer and solution

Official answer: D
From: Official GATE 2024 answer key

Solution

Sum the shares of Hydro, Solar, and Wind in 2007 and in 2023, then compute the relative percentage increase from 2007 to 2023.

Renewable share in 2007: $\text{Hydro } (30\%) + \text{Solar } (5\%) + \text{Wind } (5\%) = 40\%$
Renewable share in 2023: $\text{Hydro } (35\%) + \text{Solar } (20\%) + \text{Wind } (10\%) = 65\%$
Percentage increase in the share of renewable sources: $\frac{65\% - 40\%}{40\%} \times 100\% = \frac{25}{40} \times 100\% = 62.5\%$

Final answer

Option (D)

Common trap

Taking the absolute difference in percentage points ( $65\% - 40\% = 25\%$ ) instead of the percentage increase relative to the 2007 share.

The answer is the one in the official GATE answer key. The solution is this site's own explanation.

Source

Paper: GATE 2024 Computer Science and Information Technology - Set 2 (CS2)
Question: 8 of 65
Section: General Aptitude

Report an error in this question

GATE questions are the work of the organising institutes. This site is independent and is not affiliated with them.

Question

Solution

Source