A. there are 20 boys and 30 girls.
B.
68.7 out of 100 Boys
Girls im not sure, maybe someone else can answer that sorry
Hope I'm right and this helps sorry i didn't get girls.
Just answering for a task
H + 121 + 31 = 180
H + 152 = 180
H = 180 - 152
H = 28
1. 6:3
2. 6:2
3. 3:18
4:5:6
5:13
6:x
7:x
8: check
9:check
10: x
The solution for this problem would be:
f'(x) = 1 - 1/x^2 = (x^2 - 1)/x^2
is positive where |x| > 1
hence (-inf, -1) and (1, inf) are the regions in which f' is positive and therefore f is increasing.
Therefore, the answer is (-infinity,-1] U [1,infinity).