{"app":{"locale":"en-GB"},"problem":{"content":"

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?

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