Question 8 -

Cindy worked for 15 consecutive days, earning an average wage of $91 per day. During the first 7

days her average was $87/day, and her average wage during the last 7 days was $93/day. What was

her wage on the Sth day?

a

b.

$83

$92

c.

d

$97

$105

Her wage on the 8th day is $105 ⇒ answer d

Step-by-step explanation:

* Lets explain how to solve the problem

- The average of set of data = The sum of data/the number of data

- The sum of data = the average of set of data * the number of data

∵ Cindy worked for 15 consecutive days

∵ She is earning an average wage of $91 per day

∴ Her total earning = 91 * 15 = $1365

∵ Her average earning during the first 7 days is $87 per day

∴ Her total earning in the first 7 days = 87 * 7 = $609

∵ Her average earning during the last 7 days is $93 per day

∴ Her total earning in the last 7 days = 93 * 7 = $651

- Her total earning in the 14 days is the sum of the earning in the

first 7 days and the earning during the last 7 days

∵ Her total earning in the 14 days = 609 + 651 = $1260

∵ Her total earning in the 15 days is $1365

- To find her wage on the 8th day subtract her wage of the 14 days

from her wage of the 15 days

∴ Her wage on the 8th day = 1365 - 1260 = $105

* Her wage on the 8th day is $105