C. 5/6b = 140 (*assuming b = total number of cards) If the piles have an equal number of cards and 5 out of the 6 piles were put in the collection, 5/6 of the cards were put into the collection. The total number of cards put in the collection is 140, so 5/6b=140.
Six equal piles. Five were put in a collection which equaled 140 cards. That means there were 28 cards per pile for a total number or cards equals 168 cards so the answer is C. 5/6b = 140
