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Problem of the Week
Problem A and Solution
Counting Birds

Problem

The Wildlife Centre did a bird count for one month. They counted a total of \(828\) birds. Their results are shown in the table below, but the count for the blue jays is missing.

Bird Count
Sparrows \(234\)
Chickadees \(317\)
Blue Jays ?
Cardinals \(123\)
  1. How many blue jays did they count?

  2. Did they count more sparrows and blue jays combined than chickadees and cardinals combined?

Solution

  1. From the information in the table, we can find the total number of sparrows, chickadees, and cardinals is equal to \(234 + 317 + 123 = 674\). Since they counted a total of \(828\) birds, we can find the number of blue jays by subtracting the total number of the other birds from the overall total number of birds. That is, \(828 - 674 = 154\).

    Therefore, they counted \(154\) blue jays.

  2. They counted \(234 + 154 = 388\) sparrows and blue jays combined.
    They counted \(317 + 123 = 440\) chickadees and cardinals combined.
    So they counted more chickadees and cardinals combined.

    Alternatively, from the given data we know that they counted \(317 + 123 = 440\) chickadees and cardinals combined. Since \(440\) is more than half of \(828\), which is the total number of birds, then they must have counted more chickadees and cardinals.