Answer the question from the attachment.

Let us assume number of nickels = n,

number of dimes = d and

number of quarters = q.

Total number of coins = 844.

We can setup a statement "number of nickels + number of dimes +number of quarters = Total coins.

And we can setup an equation for the above statement as

n+d+q = 844            ---------------------equation(1).

We also given: Emilia had as many quarters as dimes.

Therefore, number of quarters = number of dimes.

So, we can setup another equation as

q = d                          ------------------------equation(2).

Also given : "twice as many nickels as dimes".

We can setup another equation for this statement as

n = twice of number of dimes

or n= 2d                -------------------------- equation (3).

We got three equations.

Let us solve system of three equation by substitution method.

Substituting q = d and  n= 2d  in equation (1), we got

n+d+q = 844      => 2d +d + d = 844.

Adding d's, we get

4d =844.

Dividing both sides by 4, we get

d = 211.

Therefore number of dimes = 211.

Let us find number of nickels and number of quarter coins now.

We know, number of quarters = number of dimes.

Therefore, number of qurters = 221.

Total number of coins = 844.

Therefore, number of nickels = 844 -  (number of quarters + number of dimes).

= 844 -(221+221) = 844 - 442

= 402.

So, the number of nickels =402.

Let us find the total values of all the coins.

A nickel = $0.05

A dime = $0.10

A quarter = $0.25.

Total value = 0.05 *(number of nickels) + 0.10*(number of dimes) + 0.25*(number of quarters).

= 0.05* 402 + 0.10 *221 + 0.25*221.

= 20.10 + 22.10 + 55.25.

= 97.45.

Therefore, total value of all 844 coins = $97.45.

Emilia had saved $97.45.