Dinesh has the same number of brothers as sisters. His sister, Lavanya, has twice as many brothers as she has sisters. How many boys and girls are in the family?
Dinesh has -> br & si br=si --------> (1) Lavanya has -> br+1 & si-1 ---- adding Dinesh and discounting Lavanya br+1=2*(si-1) --------> (2) kids= ? = 1+br+si (adding Dinesh) Combining (1) & (2) --> si+1=2si-2 --> si=3 & br=3 kids = 1+3+3 = 7
6 boys and 7 girls are available for a counselling. In how many ways, we can arrange them in a row, if middlest one is a boy and girls are sat on both the corners?
In a class there are total 63 students. The average age of girls is 24 years and that of boys is 21 years. If the average age of whole class is 22 years and 8 months, then how many boys are there in a class?
How many ways are possible to arrange 4 boys and 3 girls for a dinner, if there are two straight benches of capacity 5 and 2 persons for their sitting?
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?
