Question

22. Brian has $105 in his bank account and adds $40 each week. Kyra has $32 in her bank account and adds $48 each week. After how many weeks will Kyra have the same amount or more money in her bank account than Brian?

Answer 1

We want the money of Kyra to be greater than the money of Brian.

`105+40x<32+48x\rightarrow(1)`

In (1) Left side is for Brian and the Right side is for Kyra, by solving (1) we can find the value of x.

`105+40x<32+48x\rightarrow73+40x<48x\rightarrow73<8x`[tex]\frac{73}{8}This means that after 9.125 weeks Kyra will have more money than Brian.

So to be sure, after ten weeks, Kyra will have more money than Brian.

(If we want the answer to be rounded to the nearest week!)