Beads Arrangement CAT 2020 DILR Set

Twenty five coloured beads are to be arranged in a grid comprising of five rows and five columns. Each cell in the grid must contain exactly one bead. Each bead is coloured either Red, Blue or Green.
While arranging the beads along any of the five rows or along any of the five columns, the rules given below are to be followed:
1. Two adjacent beads along the same row or column are always of different colours.
2. There is at least one Green bead between any two Blue beads along the same row or column.
3. There is at least one Blue and at least one Green bead between any two Red beads along the same row or column.
Every unique, complete arrangement of twenty five beads is called a configuration.

Q. 1 The total number of possible configurations using beads of only two colours is:

Explanation

Correct Answer

2

Explanation

Q. 2 What is the maximum possible number of Red beads that can appear in any configuration?

Explanation

Correct Answer

9

Explanation

Q. 3 What is the minimum number of Blue beads in any configuration?

Explanation

Correct Answer

6

Explanation

Q. 4 Two Red beads have been placed in ‘second row, third column’ and ‘third row, second column’. How many more Red beads can be placed so as to maximise the number of Red beads used in the configuration?

Explanation

Correct Answer

6

Explanation