Understanding the data from the pie charts

In 2007, the renewable sources are Hydro 30%, Solar 5%, and Wind 5%, giving a total renewable share of 30 + 5 + 5 = 40%.

In 2023, the renewable sources are Hydro 35%, Solar 20%, and Wind 10%, giving a total renewable share of 35 + 20 + 10 = 65%.

The increase in renewable share (in percentage points) is 65% − 40% = 25%.

This 25% is the absolute increase in share, not the percentage increase asked in the question.

Calculating the percentage increase

Percentage increase is always measured relative to the original value, which in this problem is the 2007 share of renewable electricity generation.

The formula for percentage increase is:

Percentage increase = (Increase / Original value) × 100

Here:

• Increase in share = 65% − 40% = 25%
• Original share in 2007 = 40%

So,

Percentage increase = (25 / 40) × 100 = 62.5%

Thus, the percentage increase in the share of renewable sources of electricity generation from 2007 to 2023 is 62.5%.

Detailed explanation of each option

Option (A) 25%

This value is simply the difference between 65% and 40%, i.e., the absolute increase in share in percentage points.

The question, however, asks for percentage increase over the initial share, so this option confuses absolute change with relative change and is incorrect.

Option (B) 50%

This could arise from dividing the increase (25) by the final share (65) and computing (25 / 65) × 100 ≈ 38.46%, then incorrectly rounding or miscalculating to 50%.

The base for percentage increase must be the original share (40%), not the final share (65%), so this option is incorrect.

Option (C) 77.5%

This number may come from mis‑addition or incorrect use of the formula, for example, using wrong renewable totals or mixing in coal and gas data.

Since the correct relative change is exactly 62.5%, this value does not correspond to any meaningful step in the correct calculation and is incorrect.

Option (D) 62.5% – Correct option

Using the correct formula, the increase in renewable share is 25% and the original share is 40%, so the percentage increase is (25 / 40) × 100 = 62.5%.

This matches the standard percentage‑change computation and therefore is the correct choice.

Short, SEO‑friendly introduction

This GATE aptitude problem uses pie charts of electricity generation in 2007 and 2023 to test understanding of percentage change in data interpretation.

By carefully adding the shares of Hydro, Solar, and Wind and then applying the formula for percentage increase, the share of renewable sources of electricity generation is shown to rise from 40% to 65%, corresponding to a 62.5% increase.