Hi All,
This question is essentially about arithmetic and taking the proper notes. You can go about the math steps in a couple of different ways though - depending on how you 'see' this information.
From the prompt, we know that the farmer spent $35 on feed.... 40% of his money on chicken feed.... and the rest on goat feed. This means that for every dollar he spent, $0.40 was spent on chicken feed and $0.60 was spent on goat feed. With a total of $35 spent, we can easily break down the two totals....
(.4)($35) = $14.00 on chicken feed
The rest = $35 - $14 = $21 on goat feed
We were also told that the chicken feed was purchased at a 20% discount, which means that the farmer paid 80% of the regular price for that feed.
$14.00 = (.8)(Regular Price)
$14/.8 = (Regular Price)
$140/8 = (Regular Price)
$17.50 = (Regular Price)
We're asked what the price would have been if the farmer had bought both feeds at full price.... $21 + $17.50 = $38.50
Final Answer:
GMAT assassins aren't born, they're made,
Rich