Answer:
Step-by-step explanation:
300 minutes
2:00 p.m
Given the following:
Time taken to mark a script :
Mrs Kanja = 5mins
Miss Kanene = 4mins
Mrs Nyaga = 12 mins
Number of scripts = 160
Start time = 9:00 a.m
Rate at which each of them mark:
Mrs Kanja = t / 5
Miss Kanene = t/4
Mrs Nyaga = t/12
Combined rate :
t/5 + t/4 + t/12 = 160
(12t + 15t + 5t) / 60 = 160
32t / 60 = 160
32t = 160 * 60
32t = 9600
t = 9600 / 32
t = 300 minutes
300 minutes = 300/60 = 5hrs
9:00 a.m + 5 hours = 2:00 p.m
39
The median is the middle number
16, 23, 24, 39, 45, 78, 95
There are 7 numbers so the middle number is the 4th number
6, 23, 24, 39 , 45, 78, 95
The median is 39
√x^2-4
Given the expression
√(x+2) * √(x-2)
= √(x+2)(x-2)
Expand
= √x(x)-2x+2x-2(2)
= √x^2-4
Hence the product of the expression will give √x^2-4
For x to be acceptable x^2 - 4 = 0
x^2 = 4
x = ±√4
x = ±2
Acceptable value of x are values that are greater than or equal to ±2