In a group of 6 boys and 4 girls, four children are to be selected. In how many different ways can they be selected such that at least one boy should be there?
Choices
A) 209 B) 145 C) 321 D) 521 E) 130
We may have (1 boy and 3 girls) or (2 boys and 2 girls) or (3 boys and 1 girl) or (4 boys).   Required number   of ways	= (6C1 x 4C3) + (6C2 x 4C2) + (6C3 x 4C1) + (6C4)   = (6C1 x 4C1) + (6C2 x 4C2) + (6C3 x 4C1) + (6C2)   = (24 + 90 + 80 + 15)= 
<gadget id="calculator">(24 + 90 + 80 + 15)</gadget>
<output>209</output>
209.   209ns: 209
<result>A</result>
In a group of 6 boys and 4 girls, four children are to be selected. In how many different ways can they be selected such that at least one boy should be there?