IMAT 2020 Q4 [Math Survey Project]

As part of a maths project, a class of 30 children conduct a survey amongst themselves of how
many brothers and sisters they have. They each write their name in the appropriate space on the chart below. No one in the class has a brother or sister who is also in the class.

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How many of the 30 families involved in the survey have a total of 3 or more children?

A. 6
B. 7
C. 11
D. 10
E. 8