The desired number is the difference between the number of messages sent by the 16th day and the number sent by the 9th day:
... n = t(16) - t(9)
... n = (40×√16) - (40×√9)
... n = 40×(4 - 3) = 40
40 text messages were sent between the ninth and sixteenth day of the month.
Answer:
22 hours (B)
Step-by-step explanation:
John's velocity = 55mph
Sally's velocity = 65mph
John's time taken = x
Sally's time taken = x - 4
since they must cover the same distance.
and, distance = vel × time
Sally's vel × time = John's vel × time
55x = 65(x-4)
55x = 65x - 220
-10x = -220
x = 22 hours.
Therefore, Sally catches up after 22 hours
Answer:
5x-18=4x+7 ( vertical opposite angle)
5x-4x=7+18
x=25
Answer:
Step-by-step explanation:
Given
See attachment
Required
Find b, c and d
First, we solve for b using:
--- base angles of a parallelogram
Collect like terms
Solve for b
Then, we have:
--- opposite angles
So, we have:
The "mean" is the "average" you're used to, where you add up all the numbers and then divide by the number of numbers.