Correct Answer - Option 1 : 16 days
Given:
Devika completed the school project in = 20 days
Aarav is 25% more efficient than Devika.
Calculation:
Let the days taken by Aarav to complete the work be x
The ratio of time taken by Aarav and Devika = 125 : 100
⇒ 5 : 4
∴ 5 : 4 :: 20 : x
⇒ x = (4 × 20)/5
⇒ x = 16
∴ Aarav takes 16 days.