Correct answers only !
bob worked 15 consecutive day, earning an average wage of $90 per day. during the first 7 days his average was $87/day, and his average wage during the last 7 days was $92/day. what was his wage on the 8th day?
a. $83
b. $92
c. $97
d. $104

C. $97

Step-by-step explanation:

The average of his wage for all 15 days is the sum of all wages for the 15 days divided by 15.

average wage for 15 days = (sum of wages for the 15 days)/15

The amount of wages during a number of days is the product of the average wage of those days and the number of days.

First 7 days:

average wage: $87

number of days: 7

total wages in first 7 days = 7 * $87/day = $609

Last 7 days:

average wage: $92

number of days: 7

total wages in last 7 days = 7 * $92/day = $644

8th day:

wages of the 8th day is unknown, so we let x = wages of the 8th day

total wages of 15 days = (wages of first 7 days) + (wages of 8th day) + (wages of last 7 days)

total wages of 15 days = 609 + x + 644 = x + 1253

average wage for 15 days = (sum of wages for the 15 days)/15

average wage for 15 days = (x + 1253)/15

We are told the average for the 15 days is $90/day.

(x + 1253)/15 = 90

Multiply both sides by 15.

x + 1253 = 1350

Subtract 1253 from both sides.

x = 97

$97

step-by-step explanation: