1257 1275 1527 . . . . . . . . . . . . . . . . + 7521 the addition problem above shows 4 of the 24 different integers that can be formed by using each of the digits 1 , 25 and 7 exactly once in each integer . what is the sum t of the 24 integers ?
this is the way i solved it : total no . of different combos = 24 , total digits 4 therefore each digit must repeat 24 / 4 = 6 times in each row . . so the right most row would add up to 1 x 6 + 2 x 6 + 5 x 6 + 7 x 6 = 6 + 12 + 30 + 42 = 90 . . each row would add up to 90 , so 90 in the first means we have 9 that carries over and we get 0 , the second time its 90 + 9 and 9 stays and one 9 goes to the row to the left , so the last two digits of the sum t should be 90 ( e ) . . we could go on and solve the exact number but since only one answer choice has the last digits as 90 we need n ' t go any further . .
multiply(const_1, const_100)