The difference in age between a girl and her younger sister is 4 years

1.	The difference in age between a girl and her younger sister is 4 years. The younger sister in turn is 4 years older than her brother. The sum of the ages of the younger sister and her brother is 16. How old are the three children?
Answer» Let the age of the girl = x years. So, the age of her younger sister = (x – 4) years. Thus, the age of the brother = (x – 4 – 4) years = (x – 8) years. According to question: ⇒ (x – 4) + (x – 8) = 16 ⇒ x + x – 4 – 8 = 16 ⇒ 2x – 12 = 16 Adding 12 to both sides, we get ⇒ 2x – 12 + 12 = 16 + 12 ⇒ 2x = 28 Dividing both sides by 2, we get ⇒ 2x/2 = 28/2 ⇒ x = 14 Thus, the age of the girl = x = 14 years, The age of the younger sister = x – 4 = 14 – 4 = 10 years, The age of the younger brother = x – 8 = 14 – 8 = 6 years.

The difference in age between a girl and her younger sister is 4 years. The younger sister in turn is 4 years older than her brother. The sum of the ages of the younger sister and her brother is 16. How old are the three children?

Answer»

Let the age of the girl = x years.

So, the age of her younger sister = (x – 4) years.

Thus, the age of the brother = (x – 4 – 4) years = (x – 8) years.

According to question:

⇒ (x – 4) + (x – 8) = 16

⇒ x + x – 4 – 8 = 16

⇒ 2x – 12 = 16

Adding 12 to both sides, we get

⇒ 2x – 12 + 12 = 16 + 12

⇒ 2x = 28

Dividing both sides by 2, we get

⇒ 2x/2 = 28/2

⇒ x = 14

Thus, the age of the girl = x = 14 years,

The age of the younger sister = x – 4 = 14 – 4 = 10 years,

The age of the younger brother = x – 8 = 14 – 8 = 6 years.