Final answer:
To find the number of peanuts in the third bag, we multiply the average (86) by three to get the total number (258), then subtract the counts from the first two bags (90 and 84) to arrive at 84 peanuts in the third bag.
Step-by-step explanation:
The question involves finding the number of peanuts in the third bag when the average number of peanuts in three bags is given, along with the counts in the first and second bags. We can calculate this by first determining the total number of peanuts across all three bags, then subtracting the number we already have for the first two bags.
The average of the peanuts for the three bags is given as 86. Since there are three bags, the total number of peanuts is 3 times 86, which is 258 peanuts. The first bag contains 90 peanuts while the second bag contains 84 peanuts. The total number of peanuts in the first and second bags is therefore 90 + 84 = 174 peanuts. To find the number of peanuts in the third bag, we subtract the total we have from the first two bags from the overall total.
258 (total number of peanuts) - 174 (peanuts in first two bags) = 84 peanuts in the third bag.