ACT Math Practice

Front

What is the formula for permutations when selecting r items from n items?

Back

The formula for permutations is P(n, r) = n! / (n - r)!.

Front

How do you calculate the total arrangements of 3 plants selected from 6 different types?

Back

Use the permutation formula: P(6, 3) = 6! / (6 - 3)! = 6! / 3! = 120.

Front

What is the definition of a mixture in chemistry?

Back

A mixture is a combination of two or more substances where each substance retains its own properties.

Front

How do you find the percentage of a component in a mixture?

Back

Percentage = (Amount of component / Total amount of mixture) * 100.

Front

What is the formula to find the new concentration after adding a solvent?

Back

Let x be the amount of solvent added. New concentration = (Initial solvent + x) / (Total volume + x).

Front

What does the absolute value of a number represent?

Back

The absolute value of a number represents its distance from zero on the number line, regardless of direction.

Front

Back

Front

What is the order of operations in mathematics?

Back

The order of operations is Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right). (PEMDAS)

Front

How do you evaluate an expression with a variable?

Back

Substitute the value of the variable into the expression and then perform the operations according to the order of operations.

Front

What is the formula for calculating regular and overtime pay?

Back

Regular pay = hours worked * hourly rate; Overtime pay = overtime hours * (hourly rate * 1.5).