The london eye, a ferris wheel in england, has a diameter of 120 meters. this wheel completes a full rotation in 30 minutes at a speed which allows passengers to enter a capsule at the base of the ferris wheel without stopping the wheel. at the highest point, a capsule reaches a height of 135 meters above the ground.

Given in the problem is the diameter of the Ferris Wheel.

Thus, we can compute for the Ferris Wheel Circumference. This is the circular distance a single capsule attached to the wheel needs to do a full circle to.

Using 2 Step, we find the rate of how fast the capsule needs to be moving to complete 1 full cycle in 30 minutes.
1. Formula for computing the circumference
C =  2 x π x R

where R = Diameter divided by 2

C = 2π(120/2 )
C = 120π

2. Compute the rate or speed of the capsule / coach.
Rate or Speed = Distance to cover / Time it takes to cover
R/S = 120π/30 = 4π m/min or 12.57737 meters / min 

Google it that might work

Ithink it's b sorry if i'm wrong