Say what each step is Mr. Liu took 1100 yuan from the bank. There are two denominations of 100 yuan and 50 yuan. Among them, the number of 100 yuan is 3 / 5 of 50 yuan? Kneel down!

Say what each step is Mr. Liu took 1100 yuan from the bank. There are two denominations of 100 yuan and 50 yuan. Among them, the number of 100 yuan is 3 / 5 of 50 yuan? Kneel down!

If there are x pieces of 50 yuan face value, there are 3 / 5x pieces of 100 yuan face value
50x+100*3/5x=1100
50x+60x=1100
110x=1100
x=10
3/5x=10*3/5=6
A: there are 10 RMB with a face value of 50 yuan and 6 RMB with a face value of 100 yuan

A Mathematical Olympiad in grade six of primary school
A. B, C and D are four different natural numbers. Their product is 2004. What is the maximum sum of a + B + C + D?

To get the maximum sum, the three factors should be as small as possible
2004=1*2*3*334
So, sum max = 1 + 2 + 3 + 334 = 340

Simple calculation:
1/55+2/55+3/55+4/55+5/55+6/55+7/55+8/55+9/55+
10/55-11/155-12/155-13/155-14/155-15/155-16/155-17/155-18/155-19/155-20/155
Practical questions:
The two sisters raise 100 rabbits. One third of the rabbits raised by the elder sister is 16 more than one tenth of the ones raised by the younger sister. How many rabbits does the elder sister raise?
Thinking questions: (it's better to write the process)
The page numbers of a book are consecutive natural numbers 1, 2 and 3. When these pages are added together, a page number is added twice, and the incorrect result is 1991. What is the page number that has been added twice?

Question 1
Original formula = 55 / 55-155 / 155 = 0
Question 2
x+y=100
1/3x=1/10y+16
My sister has 60 rabbits
Question 3
1+2+3+.+62＝1953