Skip to main contentSkip to solution

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.

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?

Entered answer:

Solution

✅ Correct Answer: 6
Slide 1/2

Understanding the set :-

  1. It says, there are 25 beads to be arranged in a grid comprising of five rows and five columns.
  1. Each bead is coloured either Red, Blue or Green.
  1. we need to arrange the beads according to the rules given :

a) Two adjacent beads are always of different colour

b) There is at least one Green bead between any two Blue beads

c) There is at least one Blue and at least one Green bead between any two Red beads

This set gives information about 25 beads, which we need to arrange in a grid of 5 rows and 5 columns,

so there will be n different configurations we can make of these 25 beads arrangement.

Therefore, this is a question based set,

which we need to solve according to the question's demand.

According to the question :

Two red beads are in second row, third column and third row, second column.

We are asked to maximise the number of Red beads.

Red
Red

To maximize the Rs,

we need to move along the diagonal and also add R wherever we can see a space of 2 cells

RedRed
Red
RedRed
RedRed
Red

Now we can see that there will be maximum 6 red colored beads which satisfy the given arrangement.

Keyboard Shortcuts

  • Left arrow: Previous question
  • Right arrow: Next question
  • S key: Jump to solution
  • Q key: Jump to question