Question

In certain town, $25\%$ families own a cell phone, $15\%$ families own a scooter and $65\%$ families own neither a cell phone nor a scooter. If $1500$ families own both a cell phone and a scooter, then the total number of families in the town is:

• A. $10000$
• B. $20000$
• C. $30000$
• D. $50000$

Answer 1

The correct option is C $30000$

65% of families own neither a cell phone nor a scooter

35% of families own either a phone or a scooter

(A$\cup$B)=A+B-(A$\cap$B)

35%x=25%x+15%x-(A$\cap$B)

(A$\cap$B)=5%x=$\frac{5}{100}x=1500$

number of families=30000