Li deposited $3,400 into a savings account that pays 3% simple interest per year. how much will her investment be worth after 5 years?

First, find 3% of 3,400. 
Divide 3,400 by 100 to get 1% of it. 
3,400 / 100 = 34 
Multiply it by 3 to get 3%. 
34 x 3 = 102
That is the interest for 1 year. 
Find the interest for 5 years by
multiplying 102 by 5. 
102 x 5 = 510 
Add that interest to the original 
balance of her account. 
3,400 + 510 = 3,910 
Her investment will be worth 
$3,910 after 3 years. 
Hope this helps!