ISEE Lower Level Quantitative : Data Analysis and Probability

Study concepts, example questions & explanations for ISEE Lower Level Quantitative

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Example Questions

Example Question #31 : How To Find The Probability Of An Outcome

A bag contains differently colored balls. In it are \(\displaystyle 5\) pink balls, \(\displaystyle 6\) red balls, and \(\displaystyle 4\) green balls. What is the probability of choosing a red ball at random?

Possible Answers:

\(\displaystyle \frac{2}{3}\)

\(\displaystyle \frac{1}{5}\)

\(\displaystyle \frac{2}{5}\)

\(\displaystyle \frac{1}{3}\)

Correct answer:

\(\displaystyle \frac{2}{5}\)

Explanation:

Probability can be expressed as a fraction. The numerator represents the total number of what is being chosen and the denominator represents the total number of items that can be chosen. In this problem, there are \(\displaystyle 6\) red balls and a total of \(\displaystyle 15\) balls in the bag. This is represented as the fraction: \(\displaystyle \tfrac{6}{15}\). This can be reduced to \(\displaystyle \tfrac{2}{5}\). The answer is \(\displaystyle \tfrac{2}{5}\).

Example Question #32 : How To Find The Probability Of An Outcome

A bag contains differently colored balls. In it are \(\displaystyle 5\) pink balls, \(\displaystyle 6\) red balls, and \(\displaystyle 4\) green balls. What is the probability of choosing a pink ball at random?

Possible Answers:

\(\displaystyle \frac{2}{5}\)

\(\displaystyle \frac{2}{3}\)

\(\displaystyle \frac{1}{5}\)

\(\displaystyle \frac{1}{3}\)

Correct answer:

\(\displaystyle \frac{1}{3}\)

Explanation:

Probability can be expressed as a fraction. The numerator represents the total number of what is being chosen and the denominator represents the total number of items that can be chosen. In this problem, there are \(\displaystyle 5\) red balls and a total of \(\displaystyle 15\) balls in the bag. This is represented as the fraction: \(\displaystyle \tfrac{5}{15}\). This can be reduced to \(\displaystyle \tfrac{1}{3}\). The answer is \(\displaystyle \tfrac{1}{3}\).

Example Question #32 : How To Find The Probability Of An Outcome

A game requires you to throw a ball at some randomly-arranged colored tiles in order to win a prize. There are \(\displaystyle 20\) white tiles, \(\displaystyle 15\) blue tiles, \(\displaystyle 10\) red tiles, and \(\displaystyle 5\) black tiles. What is the probability of hitting a black tile?

Possible Answers:

\(\displaystyle \frac{1}{5}\)

\(\displaystyle \frac{1}{20}\)

\(\displaystyle \frac{1}{50}\)

\(\displaystyle \frac{1}{10}\)

Correct answer:

\(\displaystyle \frac{1}{10}\)

Explanation:

Probability can be expressed as a fraction. The numerator represents the total number of what is being chosen and the denominator represents the total number of items that can be chosen. In this problem, there are \(\displaystyle 5\) black tiles and a total of \(\displaystyle 50\) tiles. This is represented as the fraction: \(\displaystyle \tfrac{5}{50}\). This can be reduced to \(\displaystyle \tfrac{1}{10}\). The answer is \(\displaystyle \tfrac{1}{10}\).

Example Question #32 : How To Find The Probability Of An Outcome

Misha is choosing movies from a bin at a store. In the bin are \(\displaystyle 20\) action movies, \(\displaystyle 20\) comedies, \(\displaystyle 10\) documentaries, and \(\displaystyle 10\) other types of films. If she chooses randomly, what is the probability that Misha will pick out a comedy movie?

Possible Answers:

\(\displaystyle \frac{1}{3}\)

\(\displaystyle \frac{5}{6}\)

\(\displaystyle \frac{2}{5}\)

\(\displaystyle \frac{2}{3}\)

Correct answer:

\(\displaystyle \frac{1}{3}\)

Explanation:

Probability can be expressed as a fraction. The numerator represents the total number of what is being chosen and the denominator represents the total number of items that can be chosen. In this problem, there are \(\displaystyle 20\) comedy movies and a total of \(\displaystyle 60\) movies. This is represented as the fraction: \(\displaystyle \tfrac{20}{60}\). This can be reduced to \(\displaystyle \tfrac{1}{3}\). The answer is \(\displaystyle \tfrac{1}{3}\).

Example Question #31 : Outcomes

Jessica has a box of chocolates. \(\displaystyle 5\) have buttercream filling, \(\displaystyle 3\) have cherry filling, \(\displaystyle 2\) have raspberry filling, \(\displaystyle 5\) have coconut filling, and \(\displaystyle 5\) have no filling. What is the probability of Jessica choosing a chocolate with no filling?

Possible Answers:

\(\displaystyle \frac{1}{4}\)

\(\displaystyle \frac{1}{5}\)

\(\displaystyle \frac{3}{4}\)

\(\displaystyle \frac{2}{5}\)

Correct answer:

\(\displaystyle \frac{1}{4}\)

Explanation:

Probability can be expressed as a fraction. The numerator represents the total number of what is being chosen and the denominator represents the total number of items that can be chosen. In this problem, there are \(\displaystyle 5\) chocolates with no filling and a total of \(\displaystyle 20\) chocolates. This is represented as the fraction: \(\displaystyle \tfrac{5}{20}\). This can be reduced to \(\displaystyle \tfrac{1}{4}\). The answer is \(\displaystyle \tfrac{1}{4}\).

Example Question #31 : Data Analysis And Probability

A group of kids are playing duck-duck-goose. In the circle sit \(\displaystyle 8\) third graders, \(\displaystyle 4\) fourth graders, and \(\displaystyle 4\) fifth graders. What is the probability that a third or fourth grader will be chosen?

Possible Answers:

\(\displaystyle \frac{1}{8}\)

\(\displaystyle \frac{1}{2}\)

\(\displaystyle \frac{3}{4}\)

\(\displaystyle \frac{4}{5}\)

Correct answer:

\(\displaystyle \frac{3}{4}\)

Explanation:

Probability can be expressed as a fraction. The numerator represents the total number of what is being chosen and the denominator represents the total number of items that can be chosen. In this problem, there are \(\displaystyle 12\) third and fourth graders and a total of \(\displaystyle 16\) students. This is represented as the fraction: \(\displaystyle \tfrac{12}{16}\). This can be reduced to \(\displaystyle \tfrac{3}{4}\). The answer is  \(\displaystyle \tfrac{3}{4}\).

Example Question #34 : How To Find The Probability Of An Outcome

A jar contains \(\displaystyle 3\) candy bars, \(\displaystyle 2\) lollipops, and \(\displaystyle 5\) other types of sweets. What is the probability of drawing a lollipop at random from the jar?

Possible Answers:

\(\displaystyle \frac{3}{10}\)

\(\displaystyle \frac{1}{5}\)

\(\displaystyle \frac{2}{5}\)

\(\displaystyle \frac{1}{2}\)

Correct answer:

\(\displaystyle \frac{1}{5}\)

Explanation:

Probability can be expressed as a fraction. The numerator represents the total number of what is being chosen and the denominator represents the total number of items that can be chosen. In this problem, there are \(\displaystyle 2\) lollipops and a total of \(\displaystyle 10\) pieces of candy. This is represented as the fraction: \(\displaystyle \tfrac{2}{10}\). This can be reduced to \(\displaystyle \tfrac{1}{5}\). The answer is \(\displaystyle \tfrac{1}{5}\).

Example Question #35 : How To Find The Probability Of An Outcome

Jacob has \(\displaystyle 3\) mechanical pencils, \(\displaystyle 10\) colored pencils, and \(\displaystyle 2\) erasers in his bag. What is the probability of him taking out a colored pencil at random from the bag?

Possible Answers:

\(\displaystyle \frac{1}{3}\)

\(\displaystyle \frac{1}{5}\)

\(\displaystyle \frac{4}{5}\)

\(\displaystyle \frac{2}{3}\)

Correct answer:

\(\displaystyle \frac{2}{3}\)

Explanation:

Probability can be expressed as a fraction. The numerator represents the total number of what is being chosen and the denominator represents the total number of items that can be chosen. In this problem, there are \(\displaystyle 10\) colored pencils and a total of \(\displaystyle 15\) items. This is represented as the fraction: \(\displaystyle \tfrac{10}{15}\). This can be reduced to \(\displaystyle \tfrac{2}{3}\). The answer is \(\displaystyle \tfrac{2}{3}\).

Example Question #32 : Outcomes

If Justin rolls a six-sided die, what is the probability of it landing on an even number?

Possible Answers:

\(\displaystyle \frac{1}{3}\)

\(\displaystyle 2\)

\(\displaystyle \frac{1}{6}\)

\(\displaystyle \frac{1}{2}\)

Correct answer:

\(\displaystyle \frac{1}{2}\)

Explanation:

Probability can be expressed as a fraction. The numerator represents the total number of what is being chosen and the denominator represents the total number of items that can be chosen. In this problem, there are \(\displaystyle 3\) even numbers and a total of \(\displaystyle 6\) numbers on the die. This is represented as the fraction: \(\displaystyle \tfrac{3}{6}\). This can be reduced to \(\displaystyle \tfrac{1}{2}\). The answer is \(\displaystyle \tfrac{1}{2}\).

Example Question #31 : Probability

A store has a bin of books on sale. In the bin, there are \(\displaystyle 10\) novels, \(\displaystyle 6\) comic books, \(\displaystyle 5\) reference books, and \(\displaystyle 4\) picture books. What is the probability that someone will choose a novel from the bin?

Possible Answers:

\(\displaystyle \frac{1}{2}\)

\(\displaystyle {}\frac{1}{10}\)

\(\displaystyle \frac{1}{5}\)

\(\displaystyle \frac{2}{5}\)

Correct answer:

\(\displaystyle \frac{2}{5}\)

Explanation:

Probability can be expressed as a fraction. The numerator represents the total number of what is being chosen and the denominator represents the total number of items that can be chosen. In this problem, there are \(\displaystyle 10\) novels and a total of \(\displaystyle 25\) books. This is represented as the fraction: \(\displaystyle \tfrac{10}{25}\). This can be reduced to \(\displaystyle \tfrac{2}{5}\). The answer is \(\displaystyle \tfrac{2}{5}\).

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