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What will be the average of first four positive multiples of 8?

A16

B20

C32

D24

Answer:

B. 20

Read Explanation:

Solution:

Concept:

In this type of question we use the formula of sum of n natural numbers. And then divide the sum by total number of the terms.

Formula Used:

Sn = n2\frac{n}{2}(First term + last term)

⇒ n = no. of terms

⇒ First term = 8 

⇒ Last term = 32

Average = sum of all the terms / total numbers

Calculation:

Sn = 42(8+32)\frac{4}{2}(8 + 32)

⇒ Sn = 2(40)

⇒ Sn = 80

∴ Average = 804=20\frac{80}{4} = 20


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ഒരു ക്ലാസ്സിലെ 45 വിദ്യാർത്ഥികളിലെ 25 പേരുടെ ശരാശരി വയസ്സ് 16. ബാക്കിയുള്ള 20 പേരുടെ ശരാശരി വയസ്സ് 16.5 ആണ് .ക്ലാസിലെ ആകെ വിദ്യാർത്ഥികളുടെ ശരാശരി വയസ്സ് എത്ര?