There are 4 boys and 3 girls seated in a row.Find the probability that all girls are together?  Choose the correct choice from the following.
A) 1/6 B) 1/7 C) 2/7 D) 3/7 E) 4/7
Total No. of ways boys and girls can be seated = (4 + 3)= 
<gadget id="calculator">(4 + 3)</gadget>
<output>7</output>
7!= 5040   No. of ways that girls seated together =&gt;   consider 3 girls as a unit nd remaining 4 boys can be seated in any order...   So (1 + 4)= 
<gadget id="calculator">(1 + 4)</gadget>
<output>5</output>
5!= 120   And those 3 girls can be seated among themselves in 3! ways =&gt; 6   [(ie) Let g1,g2,g3 be the girls... in 6 ways they can be seated together...   g1g2g3, g1g3g2, g2g1g3, g2g3g1, g3g1g2, g3g2g1]   So prob. that all girls are together =&gt; (120 * 6)/5040 =&gt; 1/7   ANSWER:1/7
<result>B</result>
There are 4 boys and 3 girls seated in a row.Find the probability that all girls are together?