Answer:
10 minutes
Step-by-step explanation:
Let's use the variable x for the amount of coins.
The first machine can sort x coins in 15 minutes, so its speed is x/15 coins/minute.
The second machine can sort x coins in 30 minutes, so its speed is x/30 coins/minute.
If we sum the speeds, we have that the speed will be:
speed = (x/15) + (x/30) = (2x + x)/30 = 3x/30 = x/10
The total speed can sort x/10 coins per minute, that is x coins in 10 minutes.
Answer:
Step-by-step explanation:
julia : 20 miles in 1.2 hrs = (20/1.2) = 16.67 miles per hr
katie : 20 miles in 1.6 hrs = (20 / 1.6) = 12.5 miles per hr
how much faster does julia ride then katie...
16.67 - 12.5 = 4.17 rounds to 4.2 miles per hr faster <==
