24
The sum of 1 and 7 is 8. That is, 1 + 7 = 8
8 + 7 = 15
The first integer must equal 77 - 69 = 8 , since doubling it increases the sum by this amount. Similarly, the second integer must = 91 - 69 = 22. Then the third integer is 69 - 22 - 8 = 39.
15
The sum is: 8
8
76
It is: 7+8+25 = 40
Well, isn't that just a happy little question! The product of 7 and 8 is 56, which is different from the sum of 7 and 8, which is 15. Each operation brings its own unique result, just like how each brushstroke adds something special to a painting.
(7 x 8) + (8 x 8) = 15 x 8 = 120
(7*8)+(7+8) = 56+15 = 71