Cody was 165 cm tall on the first day of school this year, which was 10%, percent taller than he was on the first day of school last year. How tall was Cody on the first day of school last year?

If 165 cm is 10% taller, then the equation we can use to find the original age is:

x*1.1=165

This means that to solve for x, we just need to divide by 1.1 on both sides of the equation:

x=150

Therefore, Cody was 150 cm tall last year