Lesson Example Discussion Quiz: Class Homework |
Step-4 |
Title: Averages |
Grade: 8-a Lesson: S3-L2 |
Explanation: Let us verify the answer here with the steps. |
Description:
| Step | Type | Explanation | Answer |
|---|---|---|---|
1 |
Problem |
The average of three students ages is 32 years. The ratio between the first student’s age and the second student’s age is 27:10. If the third is 2 more than the second. What is the sum of the first and second students' ages? |
|
2 |
Hint |
Formula used |
\$"Average" = "Sum of set of numbers" / "Amount of numbers in set"\$ |
3 |
Step |
Let x be the number |
|
4 |
Step |
Then |
The age of first person = 27x The age of second person = 10x The age of third person = 10x + 2 |
5 |
Step |
By using formula, |
\$(27x + 10x + 10x + 2)/3 = 32\$ |
6 |
Step |
On Simplification |
\$47x + 2 = 32 \times 3\$ ⇒ \$47x + 2 = 96\$ ⇒ \$47x = 96-2 = 94\$ |
7 |
Step |
On Cancellation |
\$x = 94/47 = 2\$ |
8 |
Step |
The sum of first and second students' age |
27x + 10x = 37x |
9 |
= |
\$37 \times 2 = 74\$ |
|
10 |
Step |
Therefore, the sum of first and second students' age is |
74years |
Copyright © 2020-2022 saibook.us Contact: info@saibook.us Version: 1.5 Built: 26-September-2023 09:20AM EST