Explanation

Inverse proportion - Less workers = More days.

Total work = 6 workers × 8 days = 48 worker-days

For 4 workers:

Days = 48 / 4 = 12 days

Last verified on 08-11-2026

Explanation

Subtracting the lower group proportion from the upper group proportion gives the discrimination index ($0.70 - 0.55 = +0.15$).

Additional Information:

Item Discrimination (D): Measures how well an item differentiates between high-performing and low-performing student groups.

Positive Discrimination: Indicates that students who know the material overall answered correctly more often.

Updated on 30-10-2026 by Muqadas

Explanation

Principal and Operation accounts ratio is 7:5

So let principal = 7x

And operation = 5x

Rs 90000 transferred from principal to operation

So new principal = 7x - 90000

New operation = 5x + 90000

New ratio is 5:4

(7x - 90000) / (5x + 90000) = 5/4

Cross multiply

4_(7x - 90000) = 5_(5x + 90000)

28x - 360000 = 25x + 450000

28x - 25x = 450000 + 360000

3x = 810000

x = 270000

Original principal amount = 7x = 7 * 270000 = 1890000

Last verified on 24-10-2026

Explanation

• A ratio is a comparison of two or more quantities of the same kind.
• Formula:
• Ratio = Quantity 1 : Quantity 2
• Example:
• If there are 2 boys and 3 girls, the ratio of boys to girls is 2 : 3.

Last verified on 23-10-2026

Explanation

Old ratio = 20 : 1

Let students = 20, teachers = 1

New students = 20 + 50% of 20 = 20 _ 1.5 = 30

New teachers = 1 + 10% of 1 = 1 _ 1.1 = 1.1

New ratio = 30 : 1.1 = 30 / 1.1

Multiply by 10 to remove decimal = 300 / 11 = 300:11

Last verified on 20-10-2026