There are 154 beads in a rosary and all are coloured, either RED or BLUE or GREEN. The number of blue ones is three less than red and five more than green. The number of Red beads are:

Explanation:-

Let the number of red beads = X
Hence, Blue beads = (X - 3)
and Green beads = (X - 8)

According to the sum,
X + X - 3 + X - 8 = 154
or, 3X - 11 = 154
or, X = 55