I have a feeling that this question has been answered before, but here goes:
All you need to do is notice that there is a certain regularity to the tens and units digit. In order to get there, all you need to do is just go on with the series for a few more "turns"
02 07 22 67 202 607 1822 5467 16402 49207
As you can see, you get repeats every 4 terms, so you can seize the pattern:
a. for terms numbered 4k + 1, tens digit will be 0 and units digit will be 2
b. for terms numbered 4k + 2, tens digit will be 0 and units digit will be 7
c. for terms numbered 4k + 3, tens digit will be 2 and units digit will be 2
d. for terms numbered 4k, tens digit will be 6 and units digit will be 7.
Now, 35 = 32 + 3 = 4*8 + 3, so we're in case c, which puts your answer at 2 + 2 = 4.
Add the tens & units digit of the 35th term
This topic has expert replies
Source: Beat The GMAT — Problem Solving |
T1 2Vemuri wrote:Please answer with explanation
T2 7= 2(3) +1
T3 22= 7(3)+1
T4 67 = 22(3) +1
T5 202 =67(3)+1
T6 607 = 202(3)+1
Now 02 07 is alternating with 22 67. I would pair the terms.
1 (T1, T2) 02 07
2 (T3 , T4) 22 67
3 (T5, T6) 02 07
4 ( T7, T8) 22 67
.
.
.
14 (T33, T34)
T35
This leaves out T35 but let's see. So the 1st pair has 02 07, 2nd pair 22 67, 3rd pair 02 07 and so on. Now note that when the pair is odd as in the first pair we have 02 07, when even we have 22 67. So since the 14th pair (33, 34) is an even pair, we know it ends in 22 67. That means the 15 pair has 02. Since 35 is the first term in this pair we know it ends with 02. 2+0 =2. That ought to do it.
Answer is A
