Explanation

To convert 18 to binary:

18 ÷ 2 = 9 remainder 0

9 ÷ 2 = 4 remainder 1

4 ÷ 2 = 2 remainder 0

2 ÷ 2 = 1 remainder 0

1 ÷ 2 = 0 remainder 1

Binary value: 10010

Explanation

A binary number only contains digits 0 and 1.

So the correct answer is 1003.

Explanation

Let original wage = 100

Reduced wage = 50

Increased wage = 50 + 50% of 50 = 50 + 25 = 75

Loss = 100 - 75 = 25

Loss % = (25/100) × 100 = 25%

Explanation

Area of square = side²

2025 = side²

side = √2025 = 45 cm

Explanation

Let the numbers be 6x and 5x.

6x - 5x = 6

x = 6

Numbers are:

6x = 6 × 6 = 36

5x = 5 × 6 = 30

Explanation

Let daughter's age = x

Mother's age = 4x

Two years ago:

Daughter's age = x - 2

Mother's age = 4x - 2

4x - 2 = 5(x - 2)

4x - 2 = 5x - 10

x = 8

Explanation

Largest odd 3-digit number = 999

Smallest odd 3-digit number = 101

Difference = 999 - 101 = 898

Explanation

Total weight of sacks = 315 kg

Weight of 3 empty sacks = 3 × 5 kg = 15 kg

Weight of grams = 315 kg - 15 kg = 300 kg

Explanation

Let total income be x.

x - x/5 = 112000

4x/5 = 112000

x = 112000 × 5/4

x = 140000

Explanation

2/5 = 8/y

2y = 5 × 8

2y = 40

y = 40/2

y = 20