Hello creatively12In year 2000 he earns $30,000

In year 2001 he earns $(30,000+800)

In year 2002 he earns $(30,000 + 2 x 800)

...

In year 2015 he earns $(30,000 + 15 x 800)

Sum this AP, with a = 30,000, d = 800, n = 16 (yes, 16)

Then add on the amount he earns during the years 2016 to 2040 inclusive (25 years), to find his total earnings.

Grandad