Elementary school math problems .. speed.

1、50/( 1-60%-7/40)

2、40*( 1+ 1/4)*2

3、76/(50%-30%)

Respondent: heweiwei 004- level 2 2010-5-2311:42.

1.50÷ (1-60%-7/40) = 2000/9 tons.

2.40×( 1+ 1/4)×2 = 100km。

3.76 present 30%-(1-30%-1/2) = 760 pages

Respondent: Kangaroo-Level 4 2010-5-2311:44.

1、50/( 1-60%-7/40)

2、40*( 1+ 1/4)*2

3、76/(50%-30%)

It should be like this.

Respondent: Sun Qiyuan-Grade II 2010-5-2311:45.

The first question 50/( 1-60%-7/40)=2000/9 (ton)

The second question is 40 * (1+1/4) * 2 =100 (km).

The third question 76/(30%-(1-30%-50%)) = 760 (page)

Interviewee: Kaige Wow- Level 3 2010-5-2311:47.

First question

Answer: set to X.

0.6*X+50+7/40*X=X gives X=222.2.

the second question

Answer: the speed of return is 50 km/h.

The total distance is 2*50= 100 (km).

Third question

Answer: There are X pages.

0.3X+0.3X-76=0.5X solution X=760.

Interviewee: CREAT _ bee-level12010-5-2311:50.

The first question:

Solution: the total cargo volume is x tons.

Then 60% x+50+7/40× x = X.

The solution is X=2000/9.

The second question:

Solution: the return speed is 40× (1+1/4) = 50 (km/h).

Because the return time is 2 hours, the total distance is 50×2= 100km.

The third question:

Solution: Let this book have one page.

Then 30% x+(30% x-76) =1/2× x.

The solution is X=760.

Respondents: Magic Novel-Level 22010-5-2311:56.

I.50 ÷ (1-60%-7/40) 50 divided by its corresponding score.

2.40× 1.25×2 Calculate the speed of improvement, and then multiply it by time.

Three. 76÷(30%-20%) 76 divided by its corresponding score.

Responder: Ai Du Chess Level 1 2010-5-2312:14.

1. From the meaning of the question, it can be seen that the total cargo is unchanged, but it is divided into three parts, the first part is 60%, that is, 24/40, the second part is 50 tons, and the third part is 7/40, that is to say, the second part accounts for 9/40 of the total cargo, that is, 9/40 of the cargo is 50 tons.

50÷( 1-60%-7/40)

2. First of all, we should know: distance = speed × time (learned in primary school! )

Then look at the topic of cars coming and going, and know the speed when it comes (the speed when it goes is 40 kilometers per hour); On the return trip, we know the time (2h), and we can also get the speed indirectly (the speed is increased by a quarter: 40×0.25), from which we can conclude that the distance between Party A and Party B = the speed on the return trip× the time spent on the return trip.

That is, (40+40×0.25)×2.

3. After reading the questions, I can draw a conclusion: I read half of the books in two days (that is, 50% of a book in two days), but I only read 30% on the first day, so I can only read 20% on the second day, so I can draw the conclusion that the second day is less than the first day 10%. At this time, the title said that the next day was 76 pages less than the first day, so this is 76.

76 degrees (30%-20%)

Respondent: Flyer Mo-level12010-5-2312: 24.

The first question. The first step 1-60%-7/40 = 22.5% and the second step 50 divided by 22.5%= approximately equal to 222 (tons).

The second question. 40 times 5/4 = 50 (km) 50 times 2= 100 (km).

The third question. 1-50% = 50% 50%-30% = 20% 30%-20% =10% 76 divided by 10%=760 (page)

Respondent: 8945862 1 1- level 2 20 10-5-23 12:40.

1.50÷ (1-60%-7/40) = 2000/9 tons.

2.40*( 1+4/ 1)=50 (km) 50*2= 100 (km)

3. 1/2-30%=20% 76/20%=380 (page 1)

Interviewee: Kg Flower-Grade 1 20 10-5-23 12:47.

Your topic is not clear, is it? Do you use equations or not?

Did you finish it on the third day? Or is the next day less than the first day 14 tons?

1, if the goods are delivered on the third day, then

Set the cargo ***X tons.

0.4X+(0.6x * 6/ 15-3)+(0.6x * 6/ 15-3- 14)= X

0.4X+8/25X-3+8/25X- 17=X

1/25X=20

x=500

A: **500 tons

In other cases, it will be calculated separately.

2. First of all, we should know: distance = speed × time (learned in primary school! )

That is, (40+40×0.25)×2.

3. The first method: suppose this book has x pages, I read 0.3X on the first day, (0.3x-76) on the second day, and the remaining half is 0.5x. So 0.3x+(0.3x-76) = 0.5x, and x = 760 after the solution. The second method: I haven't read half of the whole book for two days, so I read 50% of the whole book two days ago and 30% on the first day, so I should read 20% of the whole book the next day, that is, 10% less than the first day and 76 pages less than the first day, so10%.

Interviewee: Shi Xiaoyu-level 1 20 10-5-23 12:54.

Jean x

1. Suppose the goods are x tons.

X-x-60% x-50 =(40 (7 out of 40) x

2.40×( 1+ 1/4)×2 = 100km。

Set x page

0.3X+0.3X-76=0.5X solution X=760.

Responder: midnight ghost song-level 2 2010-5-2313:12.

1、50÷( 1-60%-7/40)

=50÷9/40

=2000/9 (ton)

2、40×( 1+ 1/4)×2

=40×5/4×2

=50×2

= 100 km

3、76÷( 1- 1/2-30%)

=76÷20%

=380 pages

Reply: Lovely rabbit Ningning-Grade II 2010-5-2313: 21.

50/( 1-60%-7/40)

40×( 1+ 1/4)

76/(30%-( 1-30%-50%))

Respondent: Huayu Pavilion 2- Level 1 20 10-5-23 13:58.

(1) 50 ÷ (1-60%-7/40) = 2000/9 (ton)

(2) 2 ÷ (1-0 of 65438+4) × 40 = 3 320 (km)

(3)76(30%×2-50%)= 760 (pages)

Respondent: davidbaoguo- grade 2 20 10-5-23 14:48.

The first question:

Solution: the total cargo volume is x tons.

Then 60% x+50+7/40× x = X.

The solution is X=2000/9.

The second question:

Solution: the return speed is 40× (1+1/4) = 50 (km/h).

Because the return time is 2 hours, the total distance is 50×2= 100km.

The third question, 76/(50%-30%)

Interviewee: Anonymous 20 10-5-23 16:35.

1、50/( 1-60%-7/40)

2、40*( 1+ 1/4)*2

3、76/(50%-30%)

Respondent: 8462 15069- 20 10-5-23 16:40.

1-60%-7 out of 40 = 9 out of 40

50÷9/40=9/2000 tons

40×( 1+ 1/4)×2 = 100km。

76/(50%-30%) =760

Respondent: 1998 Zhou Siyi-Level 1 20 10-5-23 18:24.

The first question is 50\( 1-60%-7/40)≈ 222.2 copies/copy ratio = total.

The second problem is that the current vehicle speed is 40 * (1+1/4) = 50km/h.

50km/h*2h= 100km S=v*t Distance = speed * time.

Option 3: Let this book have X pages.

20%x+76=30%x pages of the next day+pages read less = pages read on the first day.

x=760

A: This book has 760 pages.

Interviewee: date like this-level12010-5-2319: 03.

50/( 1-60%-7/40)=2000/9 (ton)

40 * (1+1/4) * 2 =100 (km)

76/(30%-(1-30%-50%)) = 760 (page)

Interviewee: ysfxzxd- level 1 20 10-5-23 19:25.

1、50÷( 1-60%-7÷40)

2, 40 × ( 1+65438+4/0) × 2

3、76÷(50%-30%)

Interviewee: JYF/KOOC-0/998/KOOC-0//KOOC-0/09-Level 1 20/KOOC-0/0-5-23/KOOC-0/9: 50.

1. Solution (1) Assuming that the goods * * * have x tons, it will be 0.6X tons on the first day.

Because the total amount MINUS the transportation is the rest.

So the equation X-0.6x-50 = 7X divided by 40 can be listed.

The answer is 2000/9.

(2) After the first shipment, there is still 40%, that is, 40 tons of 16, but after 50 tons, 40 tons are only 7. So where did 9 of the 40 tons go? Naturally, the proportion is 50 tons, so we can divide 50 by (1-60%-7/40) = 2000/9.

2. Let the distance (1) of the solution be x.

Because the speed is increased by a quarter when returning, the return speed is 40*( 1+4 1)=50, and the distance divided by the speed equals the time.

The countable equation x divided by 50 equals 2, and the solution is X= 100.

(2) Because the speed of coming back is increased by a quarter, the speed of coming back is 40*( 1+4 1)=50, and it took two hours on the way back, so it can be calculated from the equation of speed * time = distance that it is 40 * (1+4/kloc-0.

3. Solution (1) Suppose this book has X pages, that is, he read 30%X on the first day, 30%X-76 on the second day, and the rest is 50% X.

The equation can be listed by the total number of pages-pages read = pages remaining.

X-30%X-(30%X-76)=50%X = 760。

(2) Because after reading 30% on the first day, 70% remained, 50% remained one day later, and 20% was read the next day, 76 pages were read less than the first day, so the proportion of 76 pages in the total number of pages was 10%, so Equation 76 can be divided by

Respondent: Mo Ling _ gaoyi 20 10-5-23 22:23.

First question

Let the gross tonnage be x.

rule

X*( 1-60%-7/40)=50

X=2000/9 tons

the second question

Let the total distance be x.

X/2=40*( 1+0.25)

X= 100 km

Third question

Let the total number of pages be x.

X*30%+30%*X-76=X* 1/2

X=760 pages

Respondent: Lao Wu H-II 20 10-5-24 09:07.

The first question: 222.222

50÷( 1-60%-7/40)

Total = total, you can make an equation. In addition, if the total cargo volume is 1, then the proportion of 50 tons is (1-60%-7/40).

Question 2: 100 km

Compared with the walking speed, it is increased by a quarter, so it is 40× (1+1/4) = 40+40×1/4 = 50, so the coming speed is 50 kilometers.

Question 3: 760

Half of them are 50%, so 20% of the books read the next day, 20% are 76 pages and less than 30%, that is, 10% of the books are 76 pages, of which 100 is 10, that is, 76 × 10%.

References:

Primary school math teacher.

Respondent: Qi Xiaoli-Grade 1 20 10-5-24 10:30.

First question

The total amount of goods released is x tons.

( 100%-60%)x-50=7/40 x

0.4x-50=7/40 x

X=2000/9 (ton)

the second question

When the solution comes back, the velocity v = 40× (1+1/4) = 50km/h.

The distance between party a and party b is s=vt=50×2= 100 km.

Third question