Question

On my sister's 15th birthday, she was 159 cm in height, having grown 6% since the year before. How tall was she the previous year?

Answer 1

It means that her height in this year is $106\%x$ in regards to the last year, where x is her height in last year, so:

$159=106\%x$

$159=\frac{106}{100}x$

$159=\frac{53}{50}x$

$159*50=53x$

$159*50=53x$

$7950=53x$

$150=x$