CTS Company Numerical Ability Permutation and Combination

Using the digits 1,5,2,8 four digit numbers are formed and the sum of all possible such numbers.

Read Solution (Total 1)

1,2 5, 8 - 4 numbers that can be arranged to form 4-digit number in 4! ways = 24 ways.

For totalling If we place all the 4 digit numbers formed vertically one below each other
eg
1285
2185
8125
2518
Out of 24 such arrangements each number (A or B or C or D) repeats itself in a vertical column (eg tens place or units place) = 24/ 4 = 6 times
so total of each column is (1 + 2 + 5 + 8) = 16
so each total is repeated 6 times hence total of a vertical row = 16 * 6 = 96

so total of all 4 digit numbers formed numbers is 96 (1+10+100+ 1000) = 96*(1111) = 106656
Ans: 106656
10 years agoHelpfull: Yes(6) No(1)

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