Question

Cody was 165cm, {cm}165cm 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?

Answer 1

Cody was 148.5cm on the first day of school last year.

Explanation:

10% = 0.1

165 x 0.1 = 16.5

165 - 16.5 = 148.5

Answer 2

For this case we have that Cody average 165cm in height and that represented 10% higher than last year.

Then, making a rule of three we have:

165cm ----------> 100%

x --------------------> 10%

Where "x" represents the cm that equals 10%

`x = \frac {10 * 165} {100}\\x = 16.5cm`

To know the height of Cody last year, we subtract:

`165cm-16.5cm = 148.5cm`

So, Cody had 148.5 cm on the first day of school last year.

Answer:

148.5cm