## Investigating in how many ways objects of two different colours can be grouped

### Problem 181

Published on Saturday, 9th February 2008, 01:00 pm; Solved by 1230; Difficulty rating: 70%Having three black objects B and one white object W they can be grouped in 7 ways like this:

(BBBW) | (B,BBW) | (B,B,BW) | (B,B,B,W) | (B,BB,W) | (BBB,W) | (BB,BW) |

In how many ways can sixty black objects B and forty white objects W be thus grouped?