Question

Mark invests $4200 in two different accounts. The first account paid 3 %, the second account paid 7 % in interest. At the end of the first year he had earned $186 in interest. How much was in each account?

Answer 1

Answer:

3% interest account = $2,700

7% interest account = $1,500

Step-by-step explanation:

We have to use equation to find the answer. Again, we are using simple interest to find how much is in each account.

We know, Interest = Capital x Interest rate x year

Let,

3% interest account = X

7% interest account = Y

According to the question,

X*0.03*1 + Y*0.07*1 = 186 ................. (i)

Again, X + Y = 4200 .................. (ii)

From equation (Ii), we get,

or X = 4,200 - Y ...................... (iii)

Putting the value of X in equation (i), we can get,

(4,200 - Y)*0.03*1 + Y*0.07*1 = 186

or, 126 - 0.03Y + 0.07Y = 186

or, 0.04Y = 186-126

or, 0.04Y = 60

or, Y = 1,500

Putting Y = 1,500 in equation (iii), we get

X = 4,200 - 1,500

X = 2,700

Therefore, 3% account had $2,700 balance

7% account had $1,500 balance.