Calculus Help?
posted by Matt .
I have no idea where to start?
A survey of one thousand people found that 70% of the people have a
CD player, 85% have a telephone, and 45.2% have a computer. At
least how many people have all three objects?

There is not enough information
If A is "Cd player"
B is "having telephone"
C is "having computer", we have to use the formula
Number(A or B or C)= Number(A) + Number(B) + Number(C)  Number(A and B)  Number(A and C)  Number(B and C) + Number (A and B and C)
What you are asking for is Number (A and B and C)
Can you see which data is missing?
Also do we know of the 1000 people if there are some that don't have either phone, computer or CD??