Let the original price be x.
15%X + 34 =X
X - 15%X = 34
( 100% - 15%)X=34
X = 34 ÷ (85/100)-Let me change the component number, which can also be regarded as 85÷ 100.
X=40
Cheap price = original price-selling price
=40 - 34
=6 (yuan)
2、
Suppose the total number of pages in this book is x .+×℉%
The first day of reading: 20% x pages
Read the next day: 5/8x pages ————————— 5/8.
(5/8)x - 20%x = 34
0.625x-0.2x=34
0.425x=34
x=80
Pages read on the first day = 80× 20% = 16 pages.
3. Classmate, you typed the wrong question:
A car from A to B takes a quarter of the whole journey in the first hour and 20% of the whole journey in the second hour. At this time, it is 9 kilometers away from the midpoint. How many kilometers is it between A and B?
Suppose the whole journey is x.
The remaining first hour: 1/4 x
Leave next hour: 20% x
So half of the total distance is: (1/2) x = (1/4) x+20% x+9.
{( 1/2)-( 1/4)-( 1/5)} x = 9
0.05x=9
X =180km
4. Set up a production team with an area of X mu.
Cultivated land on the first day: 25% x
Cultivated land the next day: (x-25% x) × (2/3) —————————————— two-thirds.
(X-25%X)×(2/3)-25%X=30
0.75X×(2/3)-0.25X=30
0.5X-0.25X=30
X=30÷0.25
X= 120 mu
5. Classmate, there is something wrong with your question. Oh, do you think you have the wrong number? I changed it. Do you think it's the original problem?
There are two packages of candy. The quantity of grain in the first package accounts for two-fifths of the quantity in the second package. In the first package, milk sugar accounts for 30%, and in the second package, other sugar accounts for 42%. If these two packs of sweets are combined, what is the percentage of butterscotch?
Suppose the first packet of sugar has m grains and the second packet of sugar has n grains.
m:n = 2:5 & lt; = & gt2n = 5m & lt= & gtn=2.5m
Percentage of milk sugar in total sugar = {30% m+(1-42%) n} ↓ (m+n) ×100%.
=[{ 30% m+58%×2.5m }/(m+2.5m)]× 100%
=[{(0.3+0.58×2.5)m }/{( 1+2.5)m }]× 100%
= {(1.75m)/(3.25m) }×100%-there is an m above and below the semicolon, which is omitted.
≈ 74.6%
6. The tonnage of grain stored in warehouse A is 40% less than that in warehouse B, and the tonnage of grain stored in warehouse B is a few fractions more than that in warehouse A?
Let a be x and b be y.
The sentence "the tonnage of grain stored in warehouse A is 40% less than that in warehouse B" is conversely "the tonnage of grain stored in warehouse B is 40% more than that in warehouse A", and the answer is two fifths.