Answer:
The number of seashells he have in his collection all together is <u>140</u>.
Step-by-step explanation:
Given:
Stanley has a collection of seashells. He found 35% of his collection on Florida beaches.
Stanley has 49 seashells from Florida.
Now, to find the number of seashells of his collection altogether.
Let the number of seashells all together be 
Percentage of seashells found on Florida beaches = 35%.
Number of seashells found on Florida beaches = 49.
Now, to get the number of seashells altogether we put an equation:

⇒ 
⇒ 
⇒ 
Dividing both sides by 0.35 we get:
⇒ 
Therefore, the number of seashells he have in his collection all together is 140.
They are multiplying by 4 each set of numbers
Answer:
Step-by-step explanation:
Set this up as ratio of vinegar to oil in fraction form:

That's what we're given. If we are looking to find how much oil he needs if he's using 9 ounces of vinegar, then 9 goes on top with the vinegar stuff and x goes on bottom as the unknown amount of oil:

Cross multiply to get
5x = 90 and
x = 18
Which you probably could do without the proportions. If he is using 5 ounces of vinegar and double that amount of oil, then it just makes sense that if he uses 9 ounces of vinegar he will double that amount in oil to use 18 ounces.
Answer:
i) There are 40320 possible orders
ii) There are 336 possible orders for the first 3 positions.
Step-by-step explanation:
Given: The number of finalists = 8
The number of boys = 3
The number of girls = 5
To find the number of sample point the sample space S for the number of possible orders, we need to find factorial of 8!
The number of possible orders = 8!
= 1 x 2 x 3 x 4 x 5 x 6 x 7 x 8
= 40320
ii) From all 8 finalist, we need to choose first 3 position. Here the order is important. So we use permutation.
nPr =
Here n = 8 and r = 3
Plug in n =8 and r = 3 in the above formula, we get
8P3 = 
= 
= 6.7.8
= 336
So there are 336 possible orders for the first 3 positions.
Step-by-step explanation:
2x² + 8y = 121.5
x² - 8y = 121.5
Add the equations together to eliminate the y terms.
3x² = 243
x² = 81
x = 9