1

Problem

The mean amount of time that the 20 employees of a construction company have worked for the company is 6.7 years. After one of the employees leaves the company, the mean amount of time that the remaining employees have worked for the company is reduced to 6.25 years. How many years did the employee who left the company work for the company?

2

Step

Given that the mean time worked by all 20 employees is 6.7 years, multiply the mean by the number of employees:

\$20 \times 6.7\$ = 134 years

3

Step

After one employee leaves, the mean time worked by the remaining 19 employees is given as

6.25 years

4

Step

Multiply the new mean by the number of remaining employees:

\$19 \times 6.25\$ = 118.75 years

5

Step

Subtract the total time worked by the remaining employees from the initial total time worked by all 20 employees: This gives us the time worked by the employee who left the company

134 - 118.75 = 15.25 years

6

Solution

The employee who left the company worked for 15.25 years.

7

Sumup

Please summarize steps

Choices

8

Choice-A

This option indicates the departed employee worked for 0.45 years. Initially, all 20 employees worked a total of 134 years, with a difference of 15.25 years compared to the remaining 19. This option does not align with our calculations

Wrong 0.45

9

Choice-B

This option states that the employee worked for 2.3 years. Like option A, this does not match our calculations based on the difference between the total time worked and that of remaining employees

Wrong 2.3

10

Choice-C

This option suggests that the employee who left the company worked for 9 years. However, our calculations show that the difference between the initial total time worked and the total time worked by the remaining employees is 15.25 years, which is greater than 9 years

Wrong 9

11

Choice-D

This option proposes that the employee who left the company worked for 15.25 years. According to our calculations, the difference between the initial total time worked and the total time worked by the remaining employees is indeed 15.25 years, which aligns perfectly

Correct 15.25

12

Answer

Option

D

13

Sumup

Please summarize choices