Question
In a Group of 8 boys and 6 girls, Six children are to be
selected. In how many different ways can they be selected such that at least one boy should be there?Solution
For At least 1 boy we have (1 boy and 5 girls), (2 boys and 4 girls), (3 boys and 3 girls), (4 boys and 2 girls), (5 boys and 1 girl), (6 boys) ∴ Required Number of ways = (8C1 × 6C5) + (8C2 × 6C4) + (8C3 × 6C3) + (8C4 × 6C2) + (8C5 × 6C1) + 8C6 = 48 + 420 + 1120 + 1050 + 336 + 28 = 3002 ways
Select the correct combination of mathematical signs that can sequentially replace the “@” sign and balance the following equation.
12@5@7@2@...
If 65 + 54 = 2, 71 + 62 = 10, then 73 + 83 = ?
If A denotes ‘addition’, B denotes ‘multiplication’, C denotes ‘subtraction’, and D denotes ‘division’, then what will be the value of t...
In a certain code language, '+' represents '÷', ' - ' represents ' X ', '÷' represents '+' and ' X ' represents '-'. Find out the answer to the follow...
Select the correct combination of mathematical signs to replace the '@' signs and balance the given equation.
22 @ 6 @ 18 @ 17 @ 2
A shopkeeper sells rice in such a way that the selling price of 950 gm is the same as the cost price of one kilogram. Find his gain percent.
If '+' means 'division', ' X ' means 'addition', ' - ' means 'multiplication' and '÷' means 'subtraction', then what is the value of the following expr...
If ‘+’ stands for ‘division’; ‘×’ stands for ‘addition’; ‘–’ stands for ‘multiplication’; ‘÷’ stands for ‘subtraction�...
If ‘÷’ means ‘-’, ‘-’ mean ‘+’, ‘+’ means ‘×’ and ‘×’ means ‘÷’, compute the value of the expression:
135 × ...
Which of the following interchange of sign would make the given equation correct?
45 × 9 + 5 ÷ 4 = 25
Relevant for Exams:
