Compare Brain Intensive Math Problems 5, Compare Brain Intensive Math Problems

There are not enough restrictions, and there are infinite answers.

For example, Monday sells 10,000.

Tuesday Sell 10,000.

Wednesday Sell 10,000.

Thursday Sell 10,000.

Friday Sell 10,000.

Saturday Sell 10,000.

Sunday sells for 10,000.

Monday on the first day of the month.

One week turnover 10,000.

Or build a mathematical model.

From Monday to Sunday, the daily turnover is: x1, x2...x7, hypothetical.

x2 then the total turnover y=x1+x2+x3+x4+x5+x6+x7 is divided into seven cases.

First, the first day of the month is Monday.

Restrictions apply:

5y+x1+x2=13;

Second, the first day of the month is Tuesday.

Restrictions apply:

5y+x2+x3=13;

Third, the first day of the month is Wednesday.

Restrictions apply:

5y+x3+x4=13;

Fourth, the first day of the month is Thursday.

Restrictions apply:

5y+x4+x5=13;

Fifth, the first day of the month is Friday.

Restrictions apply:

5y+x5+x6=13;

Sixth, the first day of the month is Saturday.

Restrictions apply:

5y+x6+x7=13;

7. The first day of the month is Sunday.

Restrictions apply:

5y+x7+x1=13;

Solve the answer with assumptions and constraints, and the answer is not unique.

a=1,b=2,c=3,d=4,e=5,f=6,g=7,h=8,i=9

abc+ghi=123+789=912

ade-ee=145-55=90

The letters are the first few hail numbers of Li pants, and each source can be converted into numbers and then calculated.

Analysis: The 9 yuan spent per person has included the 2 yuan hidden by the waiter (that is, *** 25 yuan + 2 yuan hidden by the waiter = 27 yuan = 3 * 9 yuan) Therefore, when calculating the composition of the 30 yuan, the 2 yuan hidden by the waiter cannot be counted, but the 1 yuan returned to each person should be added. Namely:

3 * 9 + 3 * 1 = 30 yuan is just right!

Think about it another way. The three people paid a total of 30 yuan, spent 25 yuan, and the waiter hid 2 yuan, so each person spent 9 yuan, plus the 1 yuan they shared, it was exactly 30 yuan. So the dollar was found.

Summary: This question confuses people mainly because it separates the 2 yuan from the 27 yuan, and the algorithm of the original question mistakenly believes that the 2 yuan left by the waiter is not included in the 27 yuan, so there is an error result of 1 yuan less; In fact, the 2 yuan left without permission was included in the 27 yuan, plus the 3 yuan returned, and the result was exactly 30 yuan.

Hope it helps.

The three people paid a total of 27 yuan, of which the boss took 25 yuan and the waiter took 2 yuan.

The answers to addition and multiplication are incorrect, just like 2+3=5, 2x3=6, a truth.

There are at least 1,449 eggs in the basket.

1 take, 1449 .........Finish it.

2 Nak, 1449 2 724 .........Remaining 1

3 Na, 1449 3 483 .........Finish it.

4 Nak, 1449 4 362 .........The remaining 1 and 5 were taken, 1449 5 289 .........Remainder 4

6 Na, 1449 6 241 .........Remainder 3

7 Na, 1449 7 207 .........Finish it.

8 Na, 1449 8 181 .........Remaining 1

9 Nah, 1449 9 161 .........Finish it.

After the algorithm is taken, it must be that the least common multiple of these three numbers is 63.

If the conditions of other numbers are satisfied, it must be a number with a single digit of 9. Namely:

63×n，n
……Verify the results one by one.

When n 23, 63 23 1449

Solution: The face price is 3800 yuan, the discount is 850 yuan, the voucher is 800 yuan, the first use of the voucher, 3800-3200 = 600 yuan, that is, the use of voucher 600 yuan. At this time, the discount is 850 yuan, and the postage is ten yuan.

The actual payment, 3200-850 + 10 = 2360 yuan, Xiao Wang's actual payment, 2360 * 1600 3800 = 994 yuan, the discount is, 1600-994 = 606 yuan.

Xiao Ming actually paid, 2360 * (3800-1600) 3800 = 1366 yuan, the discount is, 3800-1600-1366 = 840 yuan.

I hope it can help you, satisfied, if you have any questions, please feel free to ask.

Can this product roll be used like the first floor?