If Thursday was the day after the day before yesterday five days ago, what is the least number of days ago when Sunday was three days before the day after tomorrow ?
In a row of girls, Rita and Monika occupy the ninth places from the right end and tenth place from the left end, respectively. If they interchange their places, Rita and Monika occupy seventeenth places from the right and eighteenth place from the left, respectively. How many girls are there in the row ?
In the following list of numerals, how many 2's are followed by 1's but not preceded by 4 ? 4 2 1 2 1 4 2 1 1 2 4 4 4 1 2 2 1 2 1 4 4 2 1 4 2 1 2 1 2 4 1 4 2 1 2 4 1 4 6
Three persons A, B and C are standing in queue. There are five persons between A and B and eight persons between B and C. If there ne three persons ahead of C and 21 persons behind A, what could be the minimum number of persons in the queue ?