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.
Using those three digits it is 145.
13 + 27 + 54 + 6 = 100.
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.
Dying at the age of only 54, my grandmothers death was untimely.
78 - (6 x 9) = 78 - 54 = 24