XAT 2011 — QA & DI Question 25
Answer the following question based on the information given below.
From a group of 545 contenders, a party has to select a leader. Even after holding a series of meetings, the politicians and the general body failed to reach a consensus. It was then proposed that all 545 contenders be given a number from 1 to 545. Then they will be asked to stand on a podium in a circular arrangement, and counting would start from the contender numbered 1. The counting would be done in a clockwise fashion. The rule is that every alternate contender would be asked to step down as the counting continued, with the circle getting smaller and smaller, till only one person remains standing. Therefore the first person to be eliminated would be the contender numbered 2.
Little Pika who is five and half years old has just learnt addition. However, he does not know how to carry. For example, he can add 14 and 5, but he does not know how to add 14 and 7. How many pairs of consecutive integers between 1000 and 2000 (both 1000 and 2000 included) can Little Pika add?
Answer & solution
- A
150
- B
155
156
- D
258
- E
None of the above
Let a, b and c be three digits belonging to the set {0, 1, 2, 3, 4}
The first number of the two consecutive numbers can be of following types
âââââââ
Hence total number of pairs = 125 + 25 + 5 + 1 = 156
Hence, option (c).