In a committee, $50$ people speak French, $20$ speak Spanish and $10$ speak both Spanish and French. How many speak at least one of these two languages?
Let $F$ be the set of people in the committee who speak French, and $S$ be the set of people in the committee who speak Spanish
$\therefore n(F)=50, n(S)=20, n(S \cap F)=10$
We know that:
$n(S \cup F)=n(S)+n(F)-n(S \cap F)$
$=20+50-10$
$=70-10=60$
Thus, $60$ people in the committee speak at least one of the two languages.
A market research group conducted a survey of $1000$ consumers and reported that $720$ consumers like product $\mathrm{A}$ and $450$ consumers like product $\mathrm{B}$, what is the least number that must have liked both products?
In a certain town $25\%$ families own a phone and $15\%$ own a car, $65\%$ families own neither a phone nor a car. $2000$ families own both a car and a phone. Consider the following statements in this regard:
$1$. $10\%$ families own both a car and a phone
$2$. $35\%$ families own either a car or a phone
$3$. $40,000$ families live in the town
Which of the above statements are correct
In a class of $100$ students, $55$ students have passed in Mathematics and $67$ students have passed in Physics. Then the number of students who have passed in Physics only is
A survey shows that $73 \%$ of the persons working in an office like coffee, whereas $65 \%$ like tea. If $x$ denotes the percentage of them, who like both coffee and tea, then $x$ cannot be
In a group of students, $100$ students know Hindi, $50$ know English and $25$ know both. Each of the students knows either Hindi or English. How many students are there in the group?