(4 + 4)*4 + 4 + 4 = 42
42*3*1
3/4 of 42 = 42*3/4 = 21*3/2 = 63/2
One solution is, 31 + (2 x 4) = 31 + 8 = 39 Another is, 42 - (1 x 3) = 42 - 3 = 39
106------------------------------------------------------------------------------------------------From Rafaelrz.You can make, 4P3 = 4!/(4-3)! = 24, different 3 digit numbers using 1, 2, 3 and 4.
(4! - 3)*1*2
42 + 13
(4 + 4)*4 + 4 + 4 = 42
42*3*1
It is:(42*3)+1 = 59
-3 + 4 - 6 + 3 - 2 + 42 = 1 - 6 + 3 - 2 + 42 = - 5 + 3 - 2 + 42 = - 2 - 2 + 42 = - 4 + 42 = 38
(42 + 42) - (4 / 4)
Suppose the son is x. Then John is 2x. In 42 years, son will be x+42 and John will be 2x+42. So (2x+42)/(x+42) = 4/3 [Make sure you have the ratio the correct way around - with John first]. ie 3*(2x+42) = 4*(x+42) 6x + 3*42 = 4x + 4*42 or 2x = 42 or x = 21 So the son's current age is 21.
3/4 of 42 = 42*3/4 = 21*3/2 = 63/2
One solution is, 31 + (2 x 4) = 31 + 8 = 39 Another is, 42 - (1 x 3) = 42 - 3 = 39
4 (or eight if you count transposed arrays as being different).
3/4 of 42 = 31.5