You have some unknown integer

, and you know that adding this and the next two integers,

and

, gives a total of 57.
This means

The task is to find all three unknown integers. Notice that if you know the value of

, then you pretty much know the value of the other three integers.
To find

, solve the equation above:

So if 18 is the first integer, then others must be 19 and 20.
There are 6 nickels and 14 pennies.
There are 20 total coins.
The ratio of nickels to coins is 6:20.
Both of these are divisible by 2, so we can reduce this to 3:10.
It's 13000, just think about it....
Answer:
D = L/k
Step-by-step explanation:
Since A represents the amount of litter present in grams per square meter as a function of time in years, the net rate of litter present is
dA/dt = in flow - out flow
Since litter falls at a constant rate of L grams per square meter per year, in flow = L
Since litter decays at a constant proportional rate of k per year, the total amount of litter decay per square meter per year is A × k = Ak = out flow
So,
dA/dt = in flow - out flow
dA/dt = L - Ak
Separating the variables, we have
dA/(L - Ak) = dt
Integrating, we have
∫-kdA/-k(L - Ak) = ∫dt
1/k∫-kdA/(L - Ak) = ∫dt
1/k㏑(L - Ak) = t + C
㏑(L - Ak) = kt + kC
㏑(L - Ak) = kt + C' (C' = kC)
taking exponents of both sides, we have

When t = 0, A(0) = 0 (since the forest floor is initially clear)


So, D = R - A =

when t = 0(at initial time), the initial value of D =

You have a fraction of 3/2. 3/2=1.5
Therefore, she needs 1.5 gallons of blue paint per 1 gallon of yellow paint.