18. s = 5r^2 + 7......making r the subject
s - 7 = 5r^2
(s - 7) / 5 = r^2...by taking the sqrt of both sides, it eliminates the ^2
( sqrt (s-7)/5) = r
19. h = ut - 1/2gt^2....u = 100, t = 1 4/5(or 9/5)...g = 6.4
h = (100)(9/5) - 1/2(6.4)(9/5^2)
h = 180 - 1/2(6.4)(3.24)
h = 180 - 3.2(3.24)
h = 180 - 10.368
h = 169.632 or 169 79/125
20. sorry..do not know this one
Answer:
y= 3/5x
Step-by-step explanation:
Answer:
<em>0.615</em>
Step-by-step explanation:
The frequency table is attached below.
We have to calculate, the probability that the student preferred morning classes given he or she is a junior.
i.e 
We know that,

So,

Putting the values from the table,

Answer:
100
Step-by-step explanation:
It will help in the future to memorize your time tables
10*10 is basically 10 plus 10, 10 times but in a easier form
10+10+10+10+10+10+10+10+10+10=100
10+10=20
20+10=30
30+10=40
40+10=50
50+10=60
60+10=70
70+10=80
80+10=90
90+10=100