The average of 2 numbers is ab. If one of the number is a, the other is:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 2ab - a
Average = sum of all numbers/total numbers
Let the second number be x
average = ab (given)
ab = (a + x)/2
2ab = a + x
x = 2ab - a