Need help with mark brainlist.

Nam worked on a job for 10 days. On each of the last 2 days, he worked 2 hours more than the mean number of hours he worked per day during the first 8 days. If he worked 69 hours in all, how many hours did he work during the last 2 days together?

Respuesta :

Answer: 17 hours

Step-by-step explanation:

Given that On each of the last 2 days, he worked 2 hours more than the mean number of hours he worked per day during the first 8 days. That is he worked additional 4 hours for the two days.

Let the total hours for the 8 days = E

The mean = E/8 = 0.125E

For the two last days, he worked

( 0.125E + 2 ) × 2 = 0.25E + 4

If he worked 69 hours in all, then

E + 0.25E + 4 = 69

Collect the like terms

1.25E = 69 - 4

1.25E = 65

E = 65/1.25

E = 52.

Now find the mean of the first 8 days

Mean = 52 / 8 = 6.5 hours

Nam works during the last 2 days together for:

(6.5 + 2)×2

8.5 × 2 = 17 hours