Explanation

The kilometre is a unit of length in the metric system, equal to one thousand meters.

Explanation

A number is a perfect square (or a square number) if its square root is an integer;

that is to say, it is the product of an integer with itself.

Here, the square root of 513 is about 22.650.

Explanation

Amount of work done by A and B in 1 day = 1/30

Amount of work done by A and B in 20 days = 20 × (1/30) = 20/30 = 2/3

Remaining work – 1 – 2/3 = 1/3

A completes 1/3 work in 20 days

Amount of work A can do in 1 day = (1/3)/20 = 1/60

=> A can complete the work in 60 days

Explanation

Convert to a common denominator: 3/8 + 4/2 = 3/8 + 16/8.

Add the fractions: (3 + 16) / 8 = 19/8.

Explanation

The area of a rectangle is calculated by multiplying its length by its breadth:

Area = Length × Breadth

= 16 cm × 3 cm

= 48 cm²

Explanation

Cost Price of 56 kg rice = Rs.

(26 × 20 + 30 × 36)

= Rs. (520+1082) = Rs.1600.

Selling Price of 56 kg rice = Rs.

(56 × 30)

= Rs. 1680.

Profit = Selling Price - Cost Price = 1680 - 1600.

Profit Percentage = Profit / Cost price × 100

= 800/1600 × 100 = 5%

Explanation

A pie graph (or pie chart) is divided into sectors, where each sector represents a part of the whole.

The size of each sector corresponds to the proportion of the category it represents.

Explanation

The average is the sum divided by the number of quantities:

Average = Sum / n

115 = 1840 / n

To find 'n', multiply both sides by 'n' and then divide by 115:

n = 1840 / 115

n = 16

Explanation

25% of 200 is calculated by

multiplying 200 by 25/100,

which equals 50.

Explanation

1 kilogram (kg) of gold = 1,000 grams (g)

1 gram (g) of gold = 1,000 milligrams (mg)

1 ounce (oz) of gold ≈ 31.1 grams (g)

A kilogram is equal to 2.2 pound.

Gold density: 19.3 g/cm³

Gold melting point: 1,064°C (1,947°F)