The start is 15 and 25 so you keep on adding 25 to each of them, let's start with <u>15</u>, 15+25=40 and 40 plus 25 is 65 and 65+25 is 90 the last one is 90+25= 115, now let's move on to <u>25</u>. 25+25= 50 and the next one is 50+25=75 and then 75+25=100 and <u>100+25= 125. </u>