Answer:
Jamal borrowed $1500 at 5.2% simple interest and $1500 at 10% simple interest.
Step-by-step explanation:
Let's call x the amount borrowed at 5.2% and y the amount borrowed at 10% simple interest.
He borrowed $3000 in total, so
x + y = 3000
On the other hand, the total interest was $228, so
0.052x + 0.1y = 228
Because 0.052x is the interest for the bank and 0.1y is the interest for his friend.
Now, we can solve the first equation for y
x + y - x = 3000 - x
y = 3000 - x
Then, replace this on the second equation
0.052x + 0.1(3000 - x) = 228
Solve for x
0.052x + 0.1(3000) - 0.1x = 228
-0.048x + 300 = 228
-0.048x + 300 - 300 = 228 - 300
-0.048x = -72
-0.048x/(-0.048) = -72/(-0.048)
x = 1500
With the value of x, we can find the value of y, so
y = 3000 - x
y = 3000 - 1500
y = 1500
Therefore, Jamal borrowed $1500 at 5.2% simple interest and $1500 at 10% simple interest.