The average of 10 numbers is 7. If each number is multiplied by 12, then the average of the new set of numbers will be:
Answer & explanation
Correct answer: option 4
Average = \(\frac{sum\;of\;no.}{total\;no.}\)
Let the sum of all 10 numbers is = n
⇒ ATQ,
⇒ Average = \(\frac{n}{10}\) = 7
⇒ n = 70 --- (i)
Now each number is multiplied by 12
New sum of no.'s = 12 × n
= 12 × 70 = 840
New average = \(\frac{840}{10}\) = 84
Alternate:
*If old set of numbers is multiply by 'x', then the new average will be 'x' times of old average.*
Therefore,
⇒ New Average = 12 × 7 = 84