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:
5^4
Step-by-step explanation:
When dividing exponents with the same base, you subtract their exponents.
8-4=4
This means that 5^8 / 5^4 is equal to:
5^4
For this case, the first thing we must do is define a variable.
We have then:
n: number of days.
We now write the explicit formula that represents the problem.
We have then:
an = 4n + 15
Where,
15: crunches the first day
4: increase the number 4 each day
Answer:
An explicit formula for the number of crunches Abbie will do on day n is:
an = 4n + 15
I believe the answer is b.
