Answer:
The effect of doubling the diameter is increased the area to paint as 4 times. So, paint needed is 4 times than it was before. And the area is increased by 9 times when the diameter is increased by a factor of 3. So, paint needed is 9 times than before.
Step-by-step explanation:
Please remember the concept
If side lengths are in the ratio a : b
Then the area are in the ratio of a^2 :b^2
The volume are in the ratio of a^3 :b^3,
When diameter is doubled, the area ratio becomes [tex]x^{2} :(2x)^{2}[/tex] which is simplified to [tex]x^{2} :4x^{2}[/tex]
So, the area is increased by 4 times.
According to this concept , the diameter is increased by the scale factor 3.
Let the diameter of tank is 'x', so the diameter becomes "3x"
So, it's area ratio would be [tex]x^{2} :(3x)^{2}[/tex]
If we simplify it we get [tex]x^{2} :9x^{2}[/tex]
We conclude that area to be increased by 9 times.