Tough and Tricky questions: Word Problems.
A salesman's income consists of commission and base salary. His weekly income totals over the past 5 weeks have been $406, $413, $420, $436 and $395. What must his average (arithmetic mean) income over the next five weeks be to increase his average weekly income to $500 over the 10-week period? Choose the correct choice from the following choices:  A) $570  B) $586  C) $630  D) $686  E) $715
OFFICIAL SOLUTION:   (B) First, we need to add up the wages over the past 5 weeks: $406 + $413 + $420 + $436 + $395 = $2070.   To average $500 over 10 weeks, the salesman would need to earn: $500 × 10 406 +  413 +  420 +  436 +  395= 
<gadget id="calculator">406 +  413 +  420 +  436 +  395</gadget>
<output>2_070</output>
$2070.   To average $500 over 10 weeks, the salesman would need to earn: $500 × 10= $5000.   Subtract $2070 from $5000 to determine how much he would need to earn, in total, over the next 5 weeks to average $500 for the 10 weeks: $5000 – $2070 = $2930.   Dividing $2930 by 5 will give us the amount he needs to earn on average over the next 5 weeks: $2930/5= 
<gadget id="calculator">2930/5</gadget>
<output>586</output>
$586.   The correct answer is choice ($586).
<result>B</result>
Tough and Tricky questions: Word Problems.
A salesman's income consists of commission and base salary. His weekly income totals over the past 5 weeks have been $406, $413, $420, $436 and $395. What must his average (arithmetic mean) income over the next five weeks be to increase his average weekly income to $500 over the 10-week period?