JEE Mains 30-Jan-2023 Shift 1 Solved Paper

A horse rider covers half the distance with 5m∕ s speed. The remaining part of the distance was travelled with speed 10m∕ s for half the time and with speed 15m∕ s for other half of the time. The mean speed of the rider averaged over the whole time of motion is x∕7m∕ s. The value of x is