In november 2013, the exchange rate between australian dollars (a$) and singapore dollar (s$) offered by a money changer was a$100=s$x. in december 2013, the exchange rate offered was a$100=s$(x-5). mr neo found that, every s$65 he exchanged in december 2013, he would receive a$2 more than if he exchanged in november 2013. (a) formulate an equation in x. (b) find the value of x. (c) find the amount of singapore dollars mr neo received if he exchanged a$125 in november 2013 (with working pls)