The area of a piece of land is about 34 hectares, including 14 kinds of roses, 25 kinds of tulips, and the rest are rhododendrons. What percentage of the total area is Rhododendron?

The area of a piece of land is about 34 hectares, including 14 kinds of roses, 25 kinds of tulips, and the rest are rhododendrons. What percentage of the total area is Rhododendron?

Xiangyang flower base sells two kinds of flowers -- Lily and rose. The unit price is: rose 4 yuan / plant, Lily 5 yuan / plant

Let x roses and Y lilies be purchased, where x, y ∈ n, and 1000 ≤ x ≤ 1500, y ≥ 0
① If 1000 ≤ x ≤ 1200, then
4x+5y=9000,y=(9000-4x)/5=1800-0.8x；
② If 1200 ＜ x ≤ 1500, then
3x+5y=9000,y=(9000-3x)/5=1800-0.6x；
When sold, the gross profit f (x, y) is
f(x,y)
=5x+6.3y-9000
=① 3 y, when 1000 ≤ x ≤ 1200
=② 2X + 1.3y, when 1200 ＜ x ≤ 1500
For ①,
f(x,y)=x+1.3y
=x+1.3×1800-1.3×0.8x
=2340-0.04x,1000≤x≤1200
It can be seen that the maximum value is f (1000, y) = 2340-40 = 2300
At this time, there were 1000 roses and 1000 lilies;
For 2,
f(x,y)=2x+1.3y
=2x+1.3×1800-1.3×0.6x
=2340+1.22x,1200＜x≤1500
It can be seen that the maximum value is f (1500, y) = 2340 + 1830 = 4170
At this time, 1500 roses, 900 lilies
To sum up, purchasing 1500 roses and 900 lilies can obtain the maximum gross profit,
The maximum gross profit is 4170 yuan

There are 78 chrysanthemum, rose and tulip in the florist. Among them, chrysanthemum is more than 2 times of rose and rose is 3 times of tulip and less than 2. How many of these three kinds of flowers are there
Urgent! No equations!

The process is a little busy and troublesome. We need to be patient
Suppose you add two roses, then rose: Tulip = 3 times chrysanthemum: Rose = 2 times chrysanthemum: Tulip = 6 times
Suppose that tulips account for one share of the total, then the total number is 1 + 3 + 6 = 10
78 + 2 = 80 80 / 10 = 8 chrysanthemum: 8 * 6 = 48 tulips 8 * 1 = 8 roses 78-48-8 = 22
The formula is 78 + 2 = 80 80 / 10 = 8 8 * 6 = 48 8 * 1 = 8 78-48-8 = 22 A:——
I hope I can help you