15, 17, 19 and 21.
72, 72, and 72.
Three numbers that equal 72 are 24, 24, and 24. Another set of three numbers that equal 72 are 36, 18, and 18. Additionally, 8, 24, and 40 are another set of three numbers that equal 72.
How about: 8*9 = 72
72 = 36 + 36
145
99
67 and 5
24 & 3
-936
3 x 3 x 8 equals 72
Not sure about 720 but if the answer were to be 72 then the two numbers are 8 and 9 8 x 9 = 72 8 + 9 = 17