After 40 minutes into a race, Ryan has run ⁸₁₁ of the route while Oliver has covered only ²₁₁ of the distance. Ryan runs at the same average speed throughout the race and Oliver’s average speed is 60 m/min slower than Ryan’s. If Oliver wants to finish the race at the same time as Ryan, by how many percent should he increase his average speed by for the remaining part of the race? Round off your answer to the nearest whole number.
Extra distance that Ryan ran more than Oliver in first 40 min
= 40 x 60
= 2400 m

Fraction of the entire distance that was covered by Ryan more than Oliver in the first 40 min
= ⁸₁₁ - ²₁₁
= ⁶₁₁

⁶₁₁ of the entire distance = 2400 m
¹₁₁ of the entire distance = 2400 ÷ 6 = 400 m

Distance that Oliver ran in the first 40 min
= 2 x 400
= 800 m

Oliver's average speed
= 800 ÷ 40
= 20 m/min

Ryan's average speed
= 20 + 60
= 80 m/min

Fraction of the journey that Ryan needed to run to complete the race
= 1 - ⁸₁₁
= ³₁₁

¹₁₁ of the entire distance = 400 m
³₁₁ of the entire distance = 3 x 400 = 1200 m

Duration that Ryan would take to complete
= 1200 ÷ 80
= 15 min

Fraction of the journey that Ryan needed to run to complete the race
= 1 - ²₁₁
= ⁹₁₁

⁹₁₁ of the entire distance = 9 x 400 = 3600 m  

Speed that Oliver needs to take to complete distance at the same time as Ryan
= 3600 ÷ 15
= 240 m/min

Increase in Oliver's average speed
= 240 - 20
= 220 m/min

Percentage increase in Oliver's average speed
= ²²⁰₂₀ x 100%
≈ 1100%

Answer(s): 1100%