Explanation

Let's find the cloth required per dress:

20 meters / 4 dresses = 5 meters/dress

For 15 dresses:

15 dresses × 5 meters/dress = 75 meters

Explanation

The expression {x|x ∈ A ∨ x ∈ B} represents the set of elements that are in A or in B or in both.

This is the definition of the union of two sets, denoted as A ∪ B.

Explanation

Irrational numbers cannot be expressed as fractions and have infinite non-repeating decimals.

Examples include √2, π, which do not terminate or repeat in decimal form.

Explanation

Explanation

Explanation

Using the formula for the sum of interior angles of a polygon:

(n - 2) × 180°

For a quadrilateral, n = 4:

(4 - 2) × 180°

= 2 × 180°

= 360°

The sum of the interior angles of a quadrilateral is 360°.

Explanation

The first set {-7.2322, ..., √5, √15, 8.27541 ...} includes only irrational numbers because:

• √5 and √15 are irrational (not perfect squares).
• The decimals appear non-repeating and non-terminating.

Explanation

³√27 = ³√(3 × 3 × 3)

= ³√(3³)

= 3

Explanation

A histogram visually shows the frequency distribution using bars representing intervals.

It helps to understand the distribution and spread of continuous data.

Explanation

Given the proportion:

40 : 60 = 50 : a

Let's solve for 'a' using the proportion:

40/60 = 50/a

40a = 50 × 60

40a = 3000

a = 3000 / 40

a = 75