Answer: 
Step-by-step explanation:
Given
Cost of white-washing =Rs. 4989.60
Rate =20 per meter square
So, inside area of = 
The surface area of dome= 

The volume of air in the dome 

Answer:
D
Step-by-step explanation:
D's equation shows y equals 7.8 times x. 7.8 is the unit rate.
Answer:
12 in
Step-by-step explanation:
the scale factor of the enlarged frame is found by comparing the widths
original width : enlarged width = 2 : 6 = 1 : 3
That is 3 times the original width , then
enlarged height = 4 × 3 = 12 in
Answer:
C
Step-by-step explanation:
It is the exact opposite because when you divide by 4 you go lower and when you multiply by 4 you go higher, thus making them inverse operations
let X be number of students
and y be total cost
when 30 students (30,X)where at the gym it's costs 200 (y,200)
=that is (X,y)=(30,200)
when 70 students where at the gym
=(X,y)= (70,330)
now we find the slope
M=y2-y1/x2-x1
= 330-200/70-30
= 100/40
= 2.5=3
now
Y=Mx+b
Y=2x+b
we need to find the value of b
so,we substrate for X and Y
X=30,200
200=2(30)+b
re-arrange
B+60=200
B=200-60
=140
y=2x+140
For the other questions, I can look at the equation I got. The y-intercept (b value) is $200. That means that we are adding $200 on to the price all the time. That's the price for the empty bus. The 2x means to multiply the number of people by two and add this to the $120. So each person is $2.
hope it's helpful
and please I really need brainliest, thanks