The mean of three numbers is 15. If one of the numbers is 10, what is the mean o
Practice Questions
Q1
The mean of three numbers is 15. If one of the numbers is 10, what is the mean of the other two numbers? (2020)
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Questions & Step-by-Step Solutions
The mean of three numbers is 15. If one of the numbers is 10, what is the mean of the other two numbers? (2020)
Step 1: Understand that the mean (average) of three numbers is calculated by adding the numbers together and dividing by the total count of numbers, which is 3 in this case.
Step 2: We know the mean of the three numbers is 15. This means that if we add all three numbers together and divide by 3, we should get 15.
Step 3: Let the three numbers be 10, a, and b. We can write the equation: (10 + a + b) / 3 = 15.
Step 4: To eliminate the division, multiply both sides of the equation by 3: 10 + a + b = 15 * 3.
Step 5: Calculate 15 * 3, which equals 45. So now we have: 10 + a + b = 45.
Step 6: To find a + b, subtract 10 from both sides: a + b = 45 - 10.
Step 7: Calculate 45 - 10, which equals 35. So now we have: a + b = 35.
Step 8: To find the mean of the two numbers a and b, we use the formula: Mean of a and b = (a + b) / 2.
Step 9: Substitute a + b with 35: Mean of a and b = 35 / 2.
Step 10: Calculate 35 / 2, which equals 17.5. Therefore, the mean of the other two numbers is 17.5.
