Question

Let the average wage of a worker during $15$ consecutive working days be $\$90$ per day. If the average wages during the first $7$ days is $\$87$ per day and the average wages during the last $7$ days is $\$92$ per day, then the wage on the $8^{th}$ day is

• A. $\$97$
• B. $\$90$
• C. $\$83$
• D. $\$92$

Answer 1

The correct option is A $\$97$

Average wage for $15$ days is $90$
Total wage for $15$ days $=90\times 15$
Average wage for first $7$ days is $87$
Total wage for first $7$ days $=87\times 7$
Average wage for last $7$ days is $92$
Total wage for last $7$ days $=92\times 7$
Let the wage of $8^{th}$ day be $x$, then
$87\times 7+x+92\times 7=90\times 15\Rightarrow x=90\times 15-7\times 179=97$

Hence, the wage on $8^{th}$ day is $\$97.$