Analysis, public examination questions and answer analysis are incomprehensible and difficult to calculate. Is there a quick way?

Use 1, 2, 3, 4, 5, 6 to form different six digits, and the average value of all these six digits is ().

a 350000 b 355550 c 355555.5d 388888.5

Answer d

analyse

123456 appears the same number of times in six positions, and all six digits should be 6! All the six digits in different arrangements add up, and each digit appears 5 in everyone! Times, so everyone is equivalent to multiplying by 5! ×( 1+2+…+6)=5! ×2 1。 All the figures add up to 5! ×2 1×( 100000+ 10000+ 1000+ 100+ 10+ 1)=5! × 2/kloc-0 /×1111,so the average value of these six digits is.

Put it another way. According to the meaning of the topic, six digits are composed of six digits, so this number is calculated by permutation and combination: 6! = 6x5x3x2x 1 = 720。 Six numbers appear five times in each number! =5x4x3x2x 1= 120 times. Therefore, according to the above, the total number is: (1+2+3+4+5+6) x120x (5th power of 65438+00+4th power of 65438+00+3rd power of 65438+00+2nd power of 65438). 5438+0 1 1, so here we go back to the above calculation process, that is, 21x11/kloc-0.