Answer:
24.8 mins
Step-by-step explanation:
Time > timemark > frequency
0 – 10 > 10/2 = 5 > 5
10 – 20 > (10+20)/2 = 15 > 15
20 – 30 > (20+30)/2 = 25 > 13
30 – 40 > (30+40)/2 = 35 > 10
40 – 50 > (40+50)/2 = 45 > 7
The mean time for the 50 people is given by:
Mean = summation (mid time x frequency) / total frequency
Mean = [5x5 + 15x15 + 25x13 + 35x10 + 45x7] / 50
Mean = [25 + 225 + 325 + 350 + 315] / 50
Mean = 1240 / 50
Mean = 24.8 mins
The answer is B B B B B B B B B B
X is 15 A is 90 B is 30 and C is 60
First simplify the square roots.
√25 is 5 and √16 is 4
so the equation is 3x5 + 4x4
15+16
31

Since, we know that in Elimination method we have to first the value of "x" or either "y". For that we have to multiply a number which makes the both equation's "x" or "y" equal so that we cut cancel it and find the solution.
Here's an example:
Like, in here
Equation 1: - 2x + 3y = 9
Equation 2: - 8x - 7y = 10
We can see that in "Equation 1" the first number is "- 2x" and in "Equation 2" the first number is "-8x". So, what we do in Elimination method is that we have to make the first number of both the equations equal or same.
Eg:
- 2x + 3y = 9.
- 8x + 7y = 10--(ii)
Now,we can see that in "Equation 2" the first number is "8x" whereas in "Equation 1" the first number is "-2x". We have to multiply with any number that makes the both the first number of equation is same.
So, I'm taking the number "4" to multiply it with equation 1, which gives us the result,

Now, we've subtract both the equation to get the results.
