Question
Find the number of ways to arrange each letter of the
word 'RECREATION' such that all the vowels always come together.Solution
Number of letters = 10
Take all the vowels (EEAIO) as one entity.
Number of letters now = 5 + 1 = 6!
Number of ways to arrange all the letters = 6! ÷ 2! = 720 ÷ 2 = 360
Number of ways to arrange vowels = 5! ÷ 2! = 120 ÷ 2 = 60
Required number of ways = 360 × 60 = 21,600
- Find the wrong number, in the given number series.
2, 5, 10, 17, 26, 39, 52 Find the wrong number in the given number series.
3, 8, 15, 24, 35, 50, 63
Find the wrong number in given number series.
2372, 2356, 2320, 2256, 2156, 2048.
324, 385, 460, 549, 651, 769
- Find the wrong number in the series.
2, 3, 7, 15, 31, 63, 127 1024 3072 384 1152 145 432
112, 222, 440, 872, 1717 , 3424
10, 35, 135, 360, 760, 1136, 2285.
768 2304 288 864 106 324
9 20 63 255 1285 7716
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