Question 1080311

the average age of a brother and sister was 35 years,at 5 years ago.what will be their average age at present?
<pre>Average age 5 years ago: 35
Sum of the ages, 5 years ago: 2(35), or 70
Sum of the ages now: 70 + 2(5), or 70 + 10, or 80
Current average of the 2 ages: {{{highlight_green(matrix(1,3, 80/2, "=", 40))}}}