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

Solution:

Let X = height of Cody on the first day of school last year

Given: Y = height of Cody on the first day of school year = 165 cm

10% (X) + X=Y

.10 (X) + X=165

1.10X=165

X=165/1.1

X = 150 cm = height of Cody on the first day of school last year