At the beginning of the year, Kevin had $30 in savings and saved an additional $10 each week thereafter. Mackenzie started the year with $70 and saved $5 every week. Let KK represent the amount of money Kevin has saved tt weeks after the beginning of the year and let MM represent the amount of money Mackenzie has saved tt weeks after the beginning of the year. Graph each function and determine the interval of time when Kevin has more in savings than Mackenzie.