It depends on what you are trying to calculate but the most common way I go to find percentage is to multiply by the number in decimal for ie. 50% = .5.
If you are looking for a way to do it quickly in your head I always take find out what 10% is like in the case of 100 it would be 10 so if I want to find 15% I know I can find 10% and if I cut what 10% is in half I will find 5% so likewise if I add what 10%+5% I will end up with 15%. For example, 10% of 100 is 10 half of 10 is 5 and 10+5 equals 15. If you need to find something like 20% or 30% I know that I can find 10% and instead of dividing(cutting it in half) I can multiply by 2 or 3. 10% + 10% =20%
I hope it helps, if you have more questions let me know!
Answer:
1.5
Step-by-step explanation:
Assuming that you mean that Simon is scaling Logan's build, the scale factor is 1.5.
To find this, you divide Simon's fort height by Logans.
7.5/5 = 1.5.
Answer:
3 over 12
Step-by-step explanation:
3 over 12
Answer:

Step-by-step explanation:
The formula you wrote has the fraction the other way around. You can find that the range of a projectile is in reality approximated by the equation
, where we will use ft for distances.
From the given equation we have then
, which means
since the arcsin is the inverse function of the sin.
Since we have x = 170 ft and v = 85 ft/s, we can substitute these values from the equation written, and we will have
, and from now on we have just to use a calculator, obtaining 
Answer:
1)
.
2)
years
Step-by-step explanation:
Let Hanna's sister be
years old.
Then Hanna will be
years old.
The sum of their ages will be
years.
The statement "no more than 18" means the sum of their ages is less than or equal to 18.
The required inequality is;
.
2)
The inequality we just found is
.
We simplify to get;
.
we divide both sides by
to get;
.
Therefore the oldest age Hannah's sister can be is
years