Explanation

Multiples of 70 between 200 and 600:

210, 280, 350, 420, 490, 560

Checking the conditions:

210: hundreds (2-even), tens (1-odd) ❌

280: hundreds (2-even), tens (8-even) ❌

350: hundreds (3-odd), tens (5-odd) ✅

420: hundreds (4-even), tens (2-even) ❌

490: hundreds (4-even), tens (9-odd) ❌

560: hundreds (5-odd), tens (6-even) ❌

Last verified on 16-03-2026

Explanation

To find the number of students, we need to find the LCM of 3, 4, 6, and 8.

LCM(3, 4, 6, 8) = 24

So, the number of students is a multiple of 24.

Last verified on 16-03-2026

Explanation

The multiplicative inverse of a fraction a/b is b/a, with the same sign. So, for -3/6:

Flip the fraction: 6/-3

Simplify: -6/3

-3/6 × -6/3 = 1 (proves it's the inverse)

Last verified on 16-03-2026

Explanation

U − B contains all elements in the universal set U that are not in B, which is called the complement of B.

The standard notation for the complement of a set is B′.

Last verified on 16-03-2026

Explanation

Sales tax = 7% of 1500 = 0.07 × 1500 = Rs. 105

Total cost = 1500 + 105 = Rs. 1605

Last verified on 16-03-2026

Explanation

• Sand is primarily composed of silicon dioxide (SiO₂).
• It is a chemical compound made of silicon and oxygen atoms in a 1:2 ratio.
• SiO₂ is found in quartz, glass, and sand naturally.
• It is hard, chemically stable, and insoluble in water.

Last verified on 16-03-2026

Explanation

• Temperature is a physical quantity because it can be measured directly using a thermometer.
• It describes how hot or cold a body is without changing its chemical composition.
• Physical quantities are measurable properties like length, mass, volume, and temperature.
• Weight, force, and speed are derived quantities because they depend on mass, acceleration, or distance.

Last verified on 16-03-2026

Explanation

• Dilution refers to the process of decreasing the concentration of a solution by adding more solvent.
• While ionisation involves the formation of ions from molecules in a solution.

Last verified on 16-03-2026

Explanation

• Citric acid is a natural preservative found in many fruits, particularly in citrus fruits like lemons, oranges, and grapefruits.
• It's responsible for their sour taste and is also used as a food additive.
• Other fruits like mangoes, grapes, and strawberries also contain citric acid, although in smaller amounts.
• The presence of citric acid gives these fruits their characteristic sour taste.

Last verified on 16-03-2026

Explanation

• When light is focused in front of the retina, it creates a blurred image, indicating nearsightedness (myopia).
• This occurs because the eyeball is too long or the cornea is too steep.
• It causing light to focus before reaching the retina.

Last verified on 16-03-2026