ACT Practice 1

Front

What is the least common multiple (LCM)?

Back

The least common multiple (LCM) of two or more integers is the smallest positive integer that is divisible by each of the integers.

Front

How do you find the LCM of 3, 5, and 6?

Back

To find the LCM, list the multiples of each number: Multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30...; Multiples of 5: 5, 10, 15, 20, 25, 30...; Multiples of 6: 6, 12, 18, 24, 30...; The smallest common multiple is 30.

Front

What is the slope of a line perpendicular to a given line?

Back

The slope of a line perpendicular to another line is the negative reciprocal of the slope of the original line.

Front

How do you find the slope of the line 3x + 2y = 19?

Back

Rearranging to slope-intercept form (y = mx + b): 2y = -3x + 19; y = -3/2x + 19/2. The slope (m) is -3/2.

Front

What is the slope of the line perpendicular to 3x + 2y = 19?

Back

The slope of the line perpendicular to -3/2 is 2/3.

Front

What percentage of students come from families with only one child if 30% do?

Back

If 30% of students come from families with only one child, then 100% - 30% = 70% do not.

Front

How do you calculate the number of students not from families with only one child?

Back

If there are 7,340 students and 30% come from families with one child, then 70% do not: 0.70 * 7340 = 5,138.

Front

What is the sum of angles in a triangle?

Back

The sum of the interior angles in a triangle is always 180 degrees.

Front

If ∡B = 40° and ∡W = 75°, how do you find ∡H?

Back

Using the triangle angle sum property: ∡H = 180° - (∡B + ∡W) = 180° - (40° + 75°) = 65°.

Front

What is a complementary angle?

Back

Complementary angles are two angles whose sum is 90 degrees.