cherry-knight

20+40 = 2+4 = 6 = 60
7+8 = 8x2-1 = 16-1 = 15
60+15 = 60+10+5= 70+5 = 75

silver-tongues-blog

27+48
2+8= 10
25+40=65
65+10=75

Source: studentlifeproblems