Question

average age of 7 students is 14 when two students are dropped average age becomes 10 what is the average age of two dropped students a)22 b)24 c)12 d) 10​

Answer 1

Answer:

• Average of 7 Students = 14
• Average of 5 students = 10

• Sum of age of 7 students :

⇒ Average = Sum/Numbers

⇒ Average × Numbers = Sum

⇒ 14 × 7 = Sum

⇒ Sum = 98

• Sum of age of 5 students :

⇒ Average = Sum/Numbers

⇒ Average × Numbers = Sum

⇒ 10 × 5 = Sum

⇒ Sum = 50

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• Average age of two dropped students :

⇢ Average = Sum/Numbers

⇢ Average = (Sum of 7 - Sum of 5)/2

⇢ Average = (98 - 50)/2

⇢ Average = 48/2

⇢ Average = 24

∴ Average of two dropped students is b) 24.

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Shortcut to Solve it :

Let's say 2 dropped boys take (14 - 10) = 4 years from the average, which belongs to them. That 4 years was taken away from every 5 students.

⇢ Average = Regular Average + (Average Taken × Students)/Dropped

⇢ Average = 14 + [(14 - 10) × 5]/2

⇢ Average = 14 + [4 × 5]/2

⇢ Average = 14 + 20/2

⇢ Average = 14 + 10

⇢ Average = 24

∴ Average of two dropped students is b) 24.

Answer 2

Answer:

The correct answer of this question is $24$

Step-by-step explanation:

Given - The average age of $7$ students is $14$ when two students are dropped average age becomes $10$.

To Find  - Write what is the average age of two dropped students .

Average age of $7$ Students is = $14$

Average age of $5$ students is  = $10$

Now, sum of age of 7 students is

Average =  Sum/Numbers

= Average × Numbers = Sum

= $14$ × $7$ = Sum

= Sum = $98$

Now, Sum of age of $5$ students is

and Average = Sum/Numbers

= Average × Numbers = Sum

= $10$ × $5$ = Sum

= Sum = $50$

According to the question,

The average age of the two pupils who were dropped was:

Average = Sum/Numbers

= Average = (Sum of $7$ - Sum of $5$)/ $2$

= Average =  $(98 - 50)/2$

= Average = $48/2$

= Average = $24$

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