Bank account 1: $3000 (5% interest)
Bank account 2: $7000 (4% interest)
At the end of 1 year, the interests are:
Bank 1: 5% of $3000 = 5*3000/100
Interest 1 = $150
Bank 2: 4% of $7000 = 4*7000/100
Interest 2 = $280
The total interest is: Total = Interest 1 + Interest 2 = 150 + 280
Total = $430
The total deposited is $3000 + $7000 = $10 000
If the total interest is $430, then the percent is:
430*100/10 000 = 4.3%