1:7744

2: A 4 B 6

Solve by x y binary linear equation

X+y= 10 2x+3y=26 (A X B Y)

3. Money should be divided into 260 integers, including 1, 2, 4, 5, 10, 13, 20, 26, 52, 65,130,260. The sum of the number of years is 23, assuming that the amount of money for women in a year is 2a, then it is 3a because men spend more, so even if they are all women, 260 is equal to 46a；; And even if they are all men, 260 is equal to 69a.

Therefore 46a

Question: Marlowe is putting on makeup, Mudd is reading a book, Mary is combing her hair, and Ma Ni is getting a manicure.

27:875*96

35:J is telling the truth

Topic 2

Accelerated business collection and delivery system (adopted by the United States post office)

× 9

DCBA

Because DCBA is still four digits.

So a must be 1,

Otherwise, ABCD×9 is not a four-digit number.

And because the unit number of D×9 is 1,

So d must be 9.

Write the formula as

1 BC9

× 9

9CB 1

Because B×9 has no carry (otherwise a×9+ carry product is not four digits).

So b must be 0 (because A= 1)

And because the single digit of Cx9+8 is 0,

So c must be 8.

Namely ABCD= 1089.

Checking calculation: 1089×9=980 1.