Question
Seven people are to be arranged on seven chairs. Among
them, there are three friends who should not sit together. Find the number of valid arrangements.Solution
7 people can be arranged among themselves in 7P7 ways = 5040 ways.
Assume that the 3 friends are one entity. The total number of ways in which they can be arranged among themselves = 3! = 6 ways.
Also, the set of three friends and the other students can be arranged among themselves = 5! = 120 ways.
Thus, total number of ways in which three friends are together = 6 × 120 = 720
Thus, number of ways in which all 3 friends will not occupy consecutive seats = 5040 − 720 = 4320
(13)2 - 3127 ÷ 59 = ? x 4
Solve the following equation.
143 + 14.3 + 1.43 + 0.143 + 0.0143 =?
Simplify the following expressions and choose the correct option.
(45% of 640) ÷ 8 + (3/4 of 96) = ?
55.55% of 30000 – 1111 = ? × 1111
Find the simplified value of the following expression:
[{12 + (13 × 4 ÷ 2 ÷ 2) × 5 – 8} + 13 of 8]
24 × √? + 4008 ÷ 24 = 40% of 200 + 327
∛21952 × 44 = ? × 14
26 2 – 13% of 400 + (529 ÷ 23 2 ) = ? 2Â
- What will come in place of (?) in the given expression.
[45 + (36 ÷ 6)] × 2 – 10 = ? 25.6% of 250 + √? = 119
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