After 40 minutes into a race, Cody has run ⁸₁₁ of the route while Henry has covered only ²₁₁ of the distance. Cody runs at the same average speed throughout the race and Henry’s average speed is 93 m/min slower than Cody’s. If Henry wants to finish the race at the same time as Cody, 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 Cody ran more than Henry in first 40 min
= 40 x 93
= 3720 m

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

⁶₁₁ of the entire distance = 3720 m
¹₁₁ of the entire distance = 3720 ÷ 6 = 620 m

Distance that Henry ran in the first 40 min
= 2 x 620
= 1240 m

Henry's average speed
= 1240 ÷ 40
= 31 m/min

Cody's average speed
= 31 + 93
= 124 m/min

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

¹₁₁ of the entire distance = 620 m
³₁₁ of the entire distance = 3 x 620 = 1860 m

Duration that Cody would take to complete
= 1860 ÷ 124
= 15 min

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

⁹₁₁ of the entire distance = 9 x 620 = 5580 m  

Speed that Henry needs to take to complete distance at the same time as Cody
= 5580 ÷ 15
= 372 m/min

Increase in Henry's average speed
= 372 - 31
= 341 m/min

Percentage increase in Henry's average speed
= ³⁴¹₃₁ x 100%
≈ 1100%

Answer(s): 1100%