I'm going to assume that you meant 450kg for the combined weight, 190kg more and 3 Llamas. I'm pretty sure Llamas and Okapis don't weigh 450450450kg (that's 993,073,252 pounds). :)
x= Okapi weight
y= Llama weight
EQUATIONS:
There are 2 equations to be written:
1) 450kg is equal to the weight of one Okapi and one Llama
450kg= x + y
2) The weight of 3 llamas is equal to the weight of one Okapi plus 190kg.
3y=190kg + x
STEP 1:
Solve for one variable in one equation and substitute the answer in the other equation.
450kg= x + y
Subtract y from both sides
450-y =x
STEP 2:
Substitute (450-y) in second equation in place of x to solve for y.
3y=190kg + x
3y=190 + (450-y)
3y=640 -y
add y to both sides
4y=640
divide both sides by 4
y=160kg Llama weight
STEP 3:
Substitute 160kg in either equation to solve for x.
3y=190kg + x
3(160)=190 + x
480=190 + x
Subtract both sides by 190
290= x
x= 290kg Okapi weight
CHECK:
3y=190kg + x
3(160)=190 + 290
480=480
Hope this helps! :)
Answer:
It will take 22.5 minutes to complete 1 mile
Step-by-step explanation:
From the question,
The marching band walks 1/15 miles in 1.5 minutes
First we will determine the miles cover in 1 minute
If the marching band walks 1/15 miles in 1.5 minutes
then, they will cover
miles in 1 minute

Then,

miles
∴ 2/45 miles are covered in 1 minute
Now,
If 2/45 miles are covered in 1 minute
Then, 1 mile will be covered in
minute


∴ 
Hence, it will take 22.5 minutes to complete 1 mile
1.5r+15=2.25r
Combine like terms: 1.5r+15-1.5r=2.25r-1.5r
15=0.75r
Get the unknown alone: 15/.75=.75/.75r
20=r or r=20 :)
Answer:
a. 205320
b. 34220
c. 60! / (35)! (25)! + 60!/ (40)!(20)! + 60!/ (45)! (15)!
Step-by-step explanation:
a) The number of ways to dustribute exams among the TA's is:
n / (n - r)!
n= number of things to choose from
r= Choosing r number
60P3= 60! / (60 - 3)!
(60)(59)(58)(57)! / (57)!
=205320
B) The number of ways to dustribute the exams among the TA's is:
n! /(n - r)! r!
60C3= 60! /(60 - 3)! 3!
= 60!/ 57! 3!
= 60 × 59 × 58 / 3 × 2 × 1
= 34220
C) The required number of ways is:
60C25 + 60C20 + 60C15
= 60! / (35)! (25)! + 60!/ (40)!(20)! + 60!/ (45)! (15)!