<h2>
The crime gets cleaned up at 2:00 PM</h2>
Step-by-step explanation:
Let the work be w.
Batman can clean up all of the crime in Gotham City in 8 hours working alone.

Robin can do the same job alone in 12 hours.

Robin starts work at 8:00 AM and Batman Joins at 10:00 AM.
Let the time of completion of work after Batman's joining be t.
We have time of working of Robin = t + 10:00 -8:00 = t + 2
So

After 4 hours of 10:00 Am work gets completed.
Time = 10:00 AM + 4 hours = 2:00 PM
The crime gets cleaned up at 2:00 PM
Answer: mean=87, median=87.5 and range=18
Step-by-step explanation:
Mean:
First add all the numbers
78+95+77+92+87+79+94+86+88+94 = 870
Then you divide the answer by counting the numbers
870÷10
=87
Median:
First arrange the numbers in ascending order (from smallest to largest)
77, 78, 79, 86, 87, 88, 92, 94, 94, 95
pick the two middle numbers which is 87 and 88
then you do 
= 175÷2
= 87.5
range = Largest number - smallest number
= 95-77
= 18
Answer: Number of bags of 8. = 33
Number of bags of 10. = 31
Step-by-step explanation:
Let x = Number of bags of 8.
y = Number of bags of 10.
As per given.
(i)
(ii)
Put value of x from (ii) in (i)
Put this in (i), x= 31+2=33
Hence,
Number of bags of 8. = 33
Number of bags of 10. = 31
Since A‘(-1,1) is on the line y=-x, reflecting it about the line doesn't change its coordinate, so A's coordinate is (-1,1). Reflecting B'(-2,1) about y=-x switches both the sign and the number of x and y, so B=(-1,2), and C'(-1,0) becomes C(0,1). Drawing out the graph with the points and the line helps.
26 + 95? Use absolute values; 121.