Civil Services Punjab State Civil Services CCE 2025 Quantitative Aptitude Permutation and Combination
There are a total of 10 balls of three colours- blue, red and green in a box. The number of balls of blue colour is equal to the number of balls of green colour. Find the number of ways they can be placed in a linear row such that all the four red balls are adjacent.
1
140
2
145
3
150
4
155