Answer: 210
Step-by-step explanation:
We know that the number of combinations of n things taken r at a time is given by :-
So, number of ways to select 3 plants out of 7 =
Also number of ways to arrange them in 3 positions = 3! = 6
Now , total number of arrangements with 1 plant in each spot = (number of ways to select 3 plants out of 7) x (number of ways to arrange them in 3 positions)
= 35 x 6
=210
Hence, required number of ways = 210
Answer:
For w = 18 units perimeter is minimum
P = 2(18 + w)
Step-by-step explanation:
Given;
Area of the rectangle = 324 units²
P is the perimeter
w is the width
Let L be the length of the rectangle
therefore,
P = 2(L + w) ............(1)
also,
Lw = 324
or
L = ..........(2)
substituting 2 in 1
P =
now,
for minimizing the perimeter
= 0
or
= 0
or
= 0
or
= -1
or
w² = 324
or
w = 18 units
For w = 18 units perimeter is minimum
therefore,
from 2
L =
or
L = 18 units
objective function for P is:
P = 2(18 + w)