There are 10 marbles of different colours - red, blue, white in a bag. There are 5 more blue marbles than white marbles. Urmi takes 3 blue marbles. Meena takes 2 blue marbles and 1 red marble. Shanta takes 1 blue, 1 red and 1 white marble. What is the colour of the LAST marble remaining in the bag?

Answer 1

Number of white --- x
number of bue = x+5
number of red = 10 - x - x-5 = 5 - 2x
So clearly 5 -2x > 0
x < 2.5
so x = 1 or x = 2

case 1: x = 1 --> 1 white, 6 blue, 3 red
after the grabbing of marbles:
6 blues are taken, 2 red are taken, 1 white is taken
leaving 1 red marble

case 2: x = 2, ---> 2 white, 7 blue, 1 red
but it said 2 reds are taken and we only had one red,
So case 2 is not possible

must be case 1 , see above