Question 355436
Let s =  # calories in a sugar dud
k = # calories in a krunchy krum.  Then from the given,
{{{s = 2k-30}}}.  From the second sentence, we also know that {{{5s = 8k}}}.
Thus by direct substitution, {{{5(2k-30) = 8k}}}.
{{{10k-150 = 8k}}},
{{{2k = 150}}}, 
{{{k = 75}}}, the number of calories in a krunchy krum.  This makes {{{s = 120}}} calories for a sugar dud.