Answer:
35%
Step-by-step explanation:
easy way to remember: 
= 
= 35%
Answer: the answer is 54
Step-by-step explanation: The error in the expression was that it was multiplied by 1 so it can't be one unless it was also 1 and it's not it is 54.
Answer:
Part 1) 
Part 2)
Part 3) 
Part 4) 
Step-by-step explanation:
Part 1) Find the measure of arc AB
we know that
----> by central angle
we have

therefore

Part 2) Find the measure of arc ABC
we know that
The central angle of complete circle is equal to 360 degrees
so
Part 3) Find the measure of arc BAC
we know that
----> by angle addition postulate
we have
---> by central angle
---> by central angle
so

Part 4) Find the measure of arc ACB
we know that
The central angle of complete circle is equal to 360 degrees
so

substitute

She received 12 calls from her son and 30 calls in total.
40% of 30 is 12.