mandy wrote:

please Christoph can you explain what you are doing from y/2=x(1+r) => y=2x+2xr insert in x/y+x => x/(2x+2xr+x) => 1/(3+2r)

thanks

Mandy,

In his assumption, x is the money he saved in the first year and y is the money he spent in the first year. So the total money he earned in the first year is x+y

The question says

**Quote:**

The money he saved in the last year is what fraction of his total income, in terms of r

Thanks AJB 77 ! great explanation

a small question plz how do you get this y/2=x(1+r)

This means that the fraction needed is x/(x+y)

This has 2 variables. So you solve for y in terms of x and r based on the question and the replace y with that value in the above fraction.

Does this help?