Answer:
The answer is B
Step-by-step explanation:
Im on Edg right now and I got the answer
Answer:
18
Step-by-step explanation:
A two-digit number (xy) will have the value 10x+y. The sum of its digits is x+y.
You want ...
10x +y = 2(x +y)
1 ≤ x ≤ 9
0 ≤ y ≤ 9
The equation can be simplified to ...
8x = y
The only single-digit values for x and y that satisfy the requirements are ...
x = 1, y = 8
The two-digit number of interest is 18.
_____
<em>Check</em>
Its sum of digits is 1+8 = 9. 2×9 = 18.
_____
<em>Comment on the relationship in the problem</em>
Many of us learned our multiplication tables for 9s by remembering that the sum of digits of 9n was 9, and that the leading digit of the product was n-1.
Answer:
a) For this case we can use the definition of weighted average given by:
And if we replace the values given we have:
b) 
c) 
Step-by-step explanation:
Assuming the following question: "One sample has a mean of M=8 and a second sample has a mean of M=16 . The two samples are combined into a single set of scores.
a) What is the mean for the combined set if both of the original samples have n=4 scores
"
For this case we can use the definition of weighted average given by:
And if we replace the values given we have:
b) what is the mean for the combined set if the first sample has n=3 and the second sample has n=5
Using the definition we have:
c) what is the mean for the combined set if the first sample has n=5 and the second sample has n=3
Using the definition we have:
Answer: 9 / 11
That is approximately 0.82
Explanation:
The ratio of two quantities x and y is x divided by y, i.e. the quotient x / y.
So, the ratio of Sylia's work time to Paul's work time is:
Sylvia's work time
---------------------------
Paul's work time
Given that you have the times in mixed units, hours and minutes, you must convert to one of the, either hours or minutes.
If you choose to work with hours, this is the work:
1) Silvia's time: 3 hours and 45 minutes = 3 hours + 45 / 60 hours = 3hours + 0.75 hours = 3.75 hours
2) Paul's work time: 4 hours and 35 minutes = 4 hours + 35/60 hours = 4 hours + 7/12 hours = (48+7)/12 = 55/12 hours ≈ 4.58 hours
3) Ratio:
Sylvia's work time 3.75 hours 3.75*12 45 9
------------------------- = --------------------- = ---------------- = -------- = -----
Paul's work time (55/12) hours 55 55 11
≈ 0.82
You can calculate the ratio using minutes and shall obtain the same result. Look:
1) 3 hours + 45 minutes = 3 * 60 minutes + 45 minutes = 180 minutes + 45 minutes = 225 minutes
2) 4 hours + 35 minutes = 4*60 minutes + 35 minutes = 240 minutes + 35 minutes = 275 minutes
3)
225 minutes 9
----------------- = ------, which is the same result obtained above.
275 minutes 11
