Question

At a dance party a group of boys and girls exchange dances as follows:

one boy dances with 5 girls, a second boy dances with 6 girls, and so on, the last boy dancing with all girls. If b represents the number of boys and g the number of girls, then:

Open in App

Solution

The correct option is **C** b=g−4

Set up the following table, a one to tone correspondence between the elements of the boy set and the girl set:

Boy number =1,2,3,...b

Girl danced with =5,6,7,.....b+4;

∴ g=b+4;b=g−4

or the formula for the last term of the arithmetic sequence 5,6,7,....g;

g=5+(b−1)(1);b=g−4

Set up the following table, a one to tone correspondence between the elements of the boy set and the girl set:

Boy number =1,2,3,...b

Girl danced with =5,6,7,.....b+4;

∴ g=b+4;b=g−4

or the formula for the last term of the arithmetic sequence 5,6,7,....g;

g=5+(b−1)(1);b=g−4

0

Join BYJU'S Learning Program

Join BYJU'S Learning Program