Answer:
there were 300 beads in the box at first.
Explanation:
Let the total number of beads in the box be x.
Then, the number of red beads initially is 0.2x.
After the increase of 5%, the number of red beads becomes 1.05(0.2x) = 0.21x.
The total number of non-red beads (orange and white) initially is 0.8x.
After the increase of half, the total number of non-red beads becomes 1.5(0.8x) = 1.2x.
The total number of beads after all the increases is (0.21x) + (1.2x) = 1.41x.
Since there are 123 more beads, we can write:
1.41x - x = 123
0.41x = 123
x = 300
Therefore, there were 300 beads in the box at first.