Agatha has money in a savings account and in a certificate of deposit. The savings account pays 3% per year in interest, and the certificate pays 4%. At the end of one year, Agatha's money totals $20,000. Of this total, $750 was the money she earned in interest. Which set of equations can be used to calculate A, the amount in the savings account, and B, the amount in the certificate of deposit that she originally put in both accounts?

The set of equations are -

a + b = 19,250

(3a/100) + (4b/100) = 750

The initial deposit in the savings account = $2,000

The initial amount in the certificate of deposit = $17,250

Step-by-step explanation:

Now, let us call the savings account that Agatha made the first deposit "a" and call the certificate of deposit she made the second deposit, "b".

We learnt that her total money after one year grew to $20,000 and $750 out of this amount was the total interest she earned over the period. This means that the principals she deposited into the two accounts will be obtained by subtracting the interest from the current value of her money. That is:

$20,000 - $750 = $19,250. So, the sums she deposited into the two accounts totalled $19,250. We have an equation here;

a + b = $19,250 call this equation 1.

Again, we learnt that the first deposit (savings account) paid an interest rate of 3% yearly and the certificate of deposit paid an interest of 4% yearly.

This means that the interest yielded by the deposit in the savings account = 3/100 × a = 3a/100

And the interest yielded by the deposit in the certificate of deposit = 4/100 × b = 4b/100

We know that the interests from these two accounts was equal to $750. We have another equation now:-

3a/100 + 4b/100 = $750 call this equation 2

So we now have 2 equations that can always be used to determine the sums that were deposited in the two accounts.

a + b = 750

3a/100 + 4b/100 = 750

From equation 1 :

a + b = 19,250

a = 19,250 - b

To find the initial deposit into the savings account, we can substitute "a" for 19250 - b in equation 2.

3 × [(1950-b)/100] + (4b/100) = 750

[(5750 - 3b)/100] + (4b/100) = 750

(57750 + b)/100 = 750

57750 + b = 75000

b = 75000 - 57,750

b = 17, 250

We can then substitute "b" for 17,250 in equation 1:

a + 17,250 = 19,250

a = 19,250 - 17,250

a = $2,000

Therefore, the initial deposit in the savings account = $2,000 while the initial deposit made into the certificate of deposit = $17,250

question: how many people can she serve?

answer: she can serve 16.66666667 people. so she can only give 16 people a complete serving.

question: does she have enough ice cream for her guests?

answer: no. explanation: she only has enough for 16 people to have a full serving. however, she can give a 17th person a partial serving.