Question : The average of a certain set of 'b' numbers is 'a', and the average of a certain set of 'a' numbers is 'b'. What is the average of all the numbers taken together?
Option 1: 2b ÷ (a+b)
Option 2: 2ab ÷ (a+b)
Option 3: (a+b) ÷ 2ab
Option 4: 2a ÷ (a+b)
New: SSC MTS 2024 Application Form OUT; Direct Link
Don't Miss: Month-wise Current Affairs | Upcoming Government Exams
New: Unlock 10% OFF on PTE Academic. Use Code: 'C360SPL10'
Correct Answer: 2ab ÷ (a+b)
Solution : Average of the set of b numbers = a Average of the set of a numbers = b Average = $\frac{\text{Total sum of value}}{\text{Number of values}}$ The sum of the set of b numbers = Average × Total values The sum of the set of b numbers = a × b = ab The sum of the set of a numbers = b × a = ba Total Sum of all numbers = ab + ba = 2ab Total values = a + b Average of all numbers = $\frac{2\text{ab}}{\text{a}+\text{b}}$ Hence, the average of all the numbers taken together is $\frac{2\text{ab}}{\text{a}+\text{b}}$. Hence, the correct answer is 2ab ÷ (a+b).
Application | Cutoff | Selection Process | Preparation Tips | Eligibility | Exam Pattern | Admit Card
Question : The average of a set of 15 numbers is 41. Five numbers 21, 24, 39, 47, and 97 are removed from the above set. What will the average of the remaining 10 numbers be?
Question : The average of 5 consecutive numbers is A. If the next 3 numbers are also taken, what will be the new average?
Question : In a class, the average weight of 4 boys is 50 kg and the average weight of 4 girls is 40 kg. What is the average weight of all the 8 students taken together?
Question : The average of 20 numbers is 30 and that of the other 30 numbers is 50. What is the average of all the numbers?
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile