Explanation

Benjamin Bloom introduced the concept of Levels of Abstraction in his Bloom's Taxonomy, classifying learning objectives from simple to complex.

These levels include: Knowledge, Comprehension, Application, Analysis, Synthesis, and Evaluation—each representing deeper cognitive processing.

Explanation

Let the younger sister's present age be x.

Fareeha's present age = x + 4

After 10 years:

Younger sister's age = x + 10

Fareeha's age = x + 4 + 10 = x + 14

Given:

x + 10 + x + 14 = 48

2x + 24 = 48

2x = 24

x = 12

Fareeha's present age = x + 4

= 12 + 4

= 16 years

Explanation

Epiphytes grow on large trees to access sunlight but do not harm the host tree or take nutrients from it.

This is an example of commensalism, where one organism benefits and the other is unaffected.

Explanation

Given:

∪ = {1, 2, 3, ..., 15}

A = {2, 4, 6, ..., 14}

B = {1, 3, 5, ..., 15}

A' = ∪ - A = {1, 3, 5, ..., 15} = B

B' = ∪ - B = {2, 4, 6, ..., 14} = A

A' ∪ B' = B ∪ A = ∪ (since B and A are complementary sets that together form ∪)

Explanation

"Lying" is the present participle of "lie" (to recline), used here as a continuous action.

The sentence describes people reclining on the sofa while watching TV, so "Lying" fits grammatically.

Explanation

The points form a scalene triangle:

Calculate the distances AB, BC, and AC. If all sides are unequal, it's a scalene triangle.

AB = √((1 - (-4))² + (4 - (-2))²) = √(5² + 6²) = √61

BC = √((6 - 1)² + (11 - 4)²) = √(5² + 7²) = √74

AC = √((6 - (-4))² + (11 - (-2))²) = √(10² + 13²) = √269

All sides are unequal (√61 ≠ √74 ≠ √269), so the points form a scalene triangle.

Explanation

Step 1: Find the prime factors of each number

255 = 3 × 5 × 17

345 = 3 × 5 × 23

495 = 3² × 5 × 11

Step 2: Identify the common factors

The common prime factors are 3 and 5.

Step 3: Calculate the HCF

HCF = 3 × 5 = 15

Explanation

1/2 (sum of parallel sides × altitude) formula is derived from the fact that a trapezium can be divided into a rectangle and a triangle. 

The area of the trapezium is the sum of the areas of these two shapes, which simplifies to 1/2 × (a + b) × h, where a and b are the lengths of the parallel sides, and h is the altitude.

Explanation

The pith is the central part of the stem, mainly used for storage of nutrients and water.

It is surrounded by vascular tissues that transport water and nutrients throughout the plant.

Explanation

Problem-Based Learning (PBL) presents students with real-world, open-ended problems without a clear solution.

It encourages group collaboration, critical thinking, and self-directed learning to find solutions.