arorni wrote:
Thanks for replying back Carcass. I am trying to solve it algebraically, but each time somehow messing it up. What should be the right approach to solve this question quickly? Can you help me with the algebraic solution to this question?
For a sequence problem, the quickest approach is to build the sequence with real numbers. The algebraic approach is often too complex or time-consuming to grasp.
Let, the first number,
a1 = 0.
Now, let's put the next number,
a2 = 1.
We choose 0 and 1 as the first two numbers as this makes calculations easy.
According to the question, a2 is the average of a1 and a3. We have our a1 and a2. Now for a3, ask "1 is the average of 0 and WHAT number?"
The answer is 2, as (2+0)/2 =1.
a3 = 2So, our sequence is 0,1,2 so far.
For a4, we ask the question, "2 is the average of 1 and WHAT number?" well, that's 3.
a4=3Now we already see the pattern, it's 0,1,2,3,4,5,6,7,8...
We can easily compare Quantity A and Quantity B using this sequence. It's quite obvious now the Answer will be C.
Hope this helps!