## . The average age of a child in a class of 35 is 11. The average age, including the teacher is 12. How old is the teacher? Th

Question

. The average age of a child in a class of 35
is 11. The average age, including the
teacher is 12. How old is the teacher?
The average weight of a kid in a group of
10 is 35 kilograms. When Sonu also
joined them, the average became 36 kilo-
grams. How much does Sonu weigh?​

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1 month 2021-08-13T00:24:35+00:00 2 Answers 0 views 0

1) Given:

Average age of 35 children = 11

Average age of 35 children including the teacher = 12.

We know that,

Average= sum of observations/Number of observations.

Hence,

→ Sum of ages of 35 children/35 = 11

→ sum of ages of 35 children = 11 * 35

sum of ages of 35 children = 385 years

Similarly,

→ (sum of ages of 35 children + age of teacher )/36 = 12

→ 385 + age of teacher = 12 * 36

→ age of teacher = 432 – 385

### → age of teacher = 47 years

Hence, the age of the teacher is 47 years.

### ______________________________

2) Given:

Average weight of 10 kids = 35 kg

→ sum of weights of 10 kids/10 = 35

→ sum of weights of 10 kids = 10 * 35

sum of weights of 10 kids = 350 kg

Also,

When Sonu is joined the average becomes 36 kg.

→ (sum of weights of 10 kids + weight of Sonu)/10 + 1 = 36

→ sum of weights of 10 kids + weight of Sonu = 11 * 36

→ 350 + weight of Sonu = 396

→ weight of Sonu = 396 – 350

### → weight of Sonu = 46 kg

Therefore, the Weight of Sonu is 46 kg.

1. The average age of a child in a class of 35 students

is 11. The average age, including the teacher is 12. How old is the teacher?

Solution :

Average of 35 students is 11, when Teacher is Included the Average becomes 12.

Assume Teacher Average Age be 11 only.

He Brought (35 Students + Himself) Age as (12 – 11) = 1 year to Increase in Age Average.

According to the Question :

⇒ Teacher Age = Average + He Brought In

⇒ Teacher Age = 11 + (35 + 1) × 1

⇒ Teacher Age = 11 + 36 × 1

⇒ Teacher Age = 11 + 36

Teacher Age = 47 years

Hence, Teacher is 47 years old.

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2. The average weight of a kid in a group of 10 is 35 kilograms. When Sonu also joined them, the average became 36 kilograms. How much does Sonu weigh?

Solution :

Average of 10 kids is 35, when Sonu joined the Average becomes 36.

Assume Sonu Average Weight be 35 only.

He Brought (10 Kids + Himself) weight as (36 – 35) = 1 year to Increase in Weight Average.

According to the Question :

⇒ Sonu Weight = Average + He Brought In

⇒ Sonu Weight = 35 + (10 + 1) × 1

⇒ Sonu Weight = 35 + 11 × 1

⇒ Sonu Weight = 35 + 11

⇒ Sonu Weight = 46 kg

Hence, Sonu weighs 46 kilograms.