Question

~SIMPLE AND COMPOUND INTEREST~

Answer 1

Let's start by the easiest case, Lara's :
$800+800*(6/100)*10=1280$

Now for Carly : 6% on a year -> 3% semi anually
Hence after 10 years = 20 half years she'll have $800*(1+3/100)^20\approx1444.89$

Answer B