What is the normal time frame to walk the 10 Falls hike?

4 hours

We started from south rim that's the stone circle10am>kept on going by Canyon trail saw south falls, lower south falls 11am. continued towards North falls in the same canyon trail reached lower North falls 12pm, had lunch at double falls 45min, continued to drake falls and middle falls by 1.30pm, choose to reach north falls by same canyon trail, reached North falls and upper north falls by 2.30pm.4.5 hrs done. Returned by rim trail and reached south falls parking by 4pm- 1.5 hrs

I think it took me a couple hours but I wasn't going fast. It's better to take your time and enjoying the falls.