your answer is C. substraction
She is incorrect because 27 is not a prime number but yet it has 7 at the end
PART A - So the ruler is 22.86 centimeters tall, and after measuring with an inch ruler, is also 9 inches tall.
ruler = 22.86cm
ruler = 9 in
You can equate 22.86cm and 9in because they both equal the length of the ruler (transitive property).
22.86cm = 9in
Then you can write a proportionality equation.
Part B -
Cross multiplying,
Part C - We can use something called dimensional analysis - multiplying 12 cm by (1in/2.54cm) - in order to change the units from inches to cm. This is possible because 1in = 2.54cm, the fraction 1in/2.54cm = 1. And also the units cm will cancel out.
Let X be the number of households.
so they sent the promotional material to 21% which means 0.21X number of households get the material.
out of the 0.21x households only 0.14 respond which is
0.14(0.21x) = 0.0294x or 2.94%
2.94% is the probability that a household receives and responds.