Octavia is asking about her age. my brother is 7 years older than i am. our ages add up to 39. how old are octavia and her brother?

If we want to figure out the ages of Octavia and her brother we will need to check our information.
their ages add up to 39 and her brother is 7 years older than her 
first you will think of all numbers that equal 39; 1+38, 2+37, 3+36, 4+35, 5+34, 6+33, 7+32, 8+31, 9+30, 10+29, 11+28, 12+27, 13+26, 14+25, 15+24, 16+23, 17+22, 18+21,and 19+20
then  eliminate all the numbers that don't have a difference of 7 which will leave the following; the only numbers left are 16 and 23 

so that means that her brother is 23 and Octavia is 16