Interest from first account is :
[tex]I_1 = \dfrac{p\times r \times t}{100}\\\\I_1 = \dfrac{509\times 3.4\times 3}{100}\\\\I_1 =\$ 51.918[/tex]
Interest form second account is :
[tex]I_2 = \dfrac{p\times r\times t}{100}\\\\I_2 = \dfrac{509\times 1.7\times 3}{100}\\\\I_2 = \$25.959[/tex]
So, total interest is :
[tex]I = I_1 + I_2 \\\\I = 51.918 + 25.959\\\\I = \$77.877[/tex]
Therefore, total interest is $77.877 .
