With both of these! i need answers with work/reasoning asap!

Cody started biking to the park traveling 15 mph, after some time the bike got a flat so cody walked the rest of the way, traveling 4 mph. if the total trip to the park took 6 hours and it was 46 miles away, how long did cody travel at each speed? solve using rate times time= distance

100 points? me its important ‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️

Compute the standard deviation of the following set of data to the nearest whole number. 10, 10, 15, 20, 25