There is a percent formula for all of these types of percent problems.
It is : is/of = %/100
224 is what % of 640
is = 224
of = 640
% = x
now just sub
224/640 = x/100
cross multiply because this is a proportion
(640)(x) = (224)(100)
640x = 22400
x = 22400/640
x = 35......so 224 is 35% of 640
The answer is 600 because 1 out 3 is 60 so to find the bag multiply by two while to find 1 out 5 of her monet take 60 times 3 which is 180. 180 times 4 is the money she spent on her mobile phone so take the money spent on her mobile phone(720)minus the amount of money spent on the bag(120)
Answer:
x = 45/7
Step-by-step explanation:

Here, you can more easily see what the fractions look like.
In order to cross-multiply, you have to multiply 5 with 9, and 7 with x.
45 = 7x
Then, you isolate x by dividing 7 on both sides:
45/7 = x
Hope I helped :)
Answer: Each time the pentagon is rotated , it maps back onto itself. There are five values of for which the pentagon maps back onto itself. This is the same as the number of sides of the pentagon.
Since x and y are directly related, the equation for their comparison will look like
kx = y
where k is your constant. They give you an instance in the problem where x = 27 and y = 81. Plug this into the above equation and solve for k.
kx = y
k (27) = 81
k = 3
Thus, the constant of variation is 3.