DRDO Multi tasking staff Model paper 4

Amit is 70% more efficient than Ajay,
⇒ Efficiency Ratio of Ajay and Amit = 10 ∶ 17
⇒ Ratio of no. of days of Ajay and Amit = 17 ∶ 10 [∵ Efficiency and days are inversely proportional to each other]
Ajay can do a painting in 12 days,
⇒ 17 units = 12
⇒ 10 units = 12 × 10/17 = 120/17
∴ Amit would need 7

1

17

days to finish the same painting.