You can throw an unlimited number of darts at the dartboard. Some total scores are impossible to obtain, such as all numbers less than 5 as well as 6, 8, and 9. What is the highest whole number score that is impossible to obtain?

Question

anonymous · Answer

Here's the choices 
31

18

23

29

anonymous · Answer

I think 23

calculusxy · Answer

Yes you're correct according to the Frobenius number of (a,b)

welshfella · Answer

I dont get this question

calculusxy · Answer

This is basically with the formula from Frobenius number of (a,b) 

$$(a,b) $$ is 
$$(a \times b) - a - b $$

calculusxy · Answer

Thus, if we have a = 5 and b = 7 we will get 
$$(5 \times 7) - 5 - 7 = 35 - 5 - 7 =20 - 7 = 23 $$