So, the sphere went from 1.2 meters to 1.4 meters.
The radius will always be half of the diameter. So it went from .6 to .7.
Let's divide and see what percent .7 is of .6.
.7÷.6=1.166666666(repeating 6).
This means, it increased by about 16.7%, since it was not doubling, just going up.
For # 1, the answer will be 1 because of the exponential rule

.
#2, the answer is going to be

because of the exponential rule

.
#3. I'm not sure that this could be simplified any further.
#4 To get the answer to this question, we must apply the distributive property, along with the exponential rule
. When we apply these properties, we'll get

For the other questions, they all apply the Laws of Exponents.
The car is faster because it’s 120km/hr, wile the train is 75km/hr
The relation between a and s is given to be:
a = 640s
where,
a = number of acres
s = number of square miles
We are to find the number of acres for 7.5 square miles.
This means, s = 7.5
Using the value in the formula, we get:
a = 640 x 7.5 = 4800 acres
So the answer to this question is option B
C = 5/9(F - 32)
F = 62
C = 5/9(62 - 32)
C = 5/9(30)
C = 150/9
C = 16.7 <===