[email protected] wrote:Mark has 60 blue marbles, half of which are checked, 50 checked marbles, half of which are oval, and 40 oval marbles, half of which are blue. If 10 marbles Mark has are blue, checked and oval and all the marbles he has are either blue, checked or oval, then how many total marbles Mark has?
Draw a VENN DIAGRAM representing the following:
Mark has 60 blue marbles, 50 checked marbles, and 40 oval marbles.
Complete the Venn diagram by working from the INSIDE OUT.
10 marbles Mark has are blue, checked and oval.
60 blue marbles, half of which are checked = 30 blue and checked.
50 checked marbles, half of which are oval = 25 checked and oval.
40 oval marbles, half of which are blue = 20 oval and blue.
Subtracting from 30, 25 and 20 the 10 marbles that are in all 3 groups, we get:
Subtracting the values in the diagram from B=60, C=50, and O=40, we get:
How many total marbles does Mark have?
Adding together the values in the Venn Diagram, we get:
T = 20+20+5+10+10+15+5 =
85.
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