Megan answered 18 questions correctly on a test. that is 75% of the total number of questions. how many questions were on the test?

51

step-by-step explanation:

73-22=51 the   mass number minus the amount of protons gives you the amount of neutrons

step-by-step explanation:

if you want to solve percent error follow these steps.

1. subtract the accepted value from the experimental value.

2. take the absolute value of step 1.

3. divide that answer by the accepted value.

4. multiply that answer by 100 and add the % symbol to express the answer as a percentage.

if you want to solve percent of change just do this.

1. work out the difference (increase) between the two numbers you are comparing.

2. divide the increase by the original number and multiply the answer by 100. if your answer is a negative number then this is a percentage decrease.

hope this : )