One possible solution: 8 * 6 + average(5, 7)
It looks like there's only one solution: 9 * 6 = 54; 6 * 5 = 30; 54 - 30 = 24.
(6 x 13) - (6 x 9) = 78 - 54 = 24
54 = 6/(1 - 8/9).
I believe this is this weeks car talk puzzler. It only takes 4 but if you write out the equation the final 4 is in the answer. 4!+4!+4+sqrt(4)=54
Once with a remainder of 39
For now there are only 54
54 can go into 54 once, with remainder 4.
If the three digits are to be used once only then the greatest fraction is 54/3. If the required fraction is less than 1 then the solution is 5/34.
13 + 27 + 54 + 6 = 100.
Using those three digits it is 145.
Dying at the age of only 54, my grandmothers death was untimely.
78 - (6 x 9) = 78 - 54 = 24