For a training run, a triathlete covers 50 km in 4 1/4 hours. She runs part of the way at a speed of 10km/h, cycles part of the way at 40km/h and swims the remaining distance at 2 1/2 km/h. The athlete runs for twice the time it takes to complete the cycle leg. How long did she take to complete the cycle leg? (If you can show your working out, I will give you brainliest). Thanks