<span>you could have 3.15=100 times 0.0315, 10 times 0.315.</span>
$5000 is the correct answer.
The formula for simple interest is I=prt. Anson gets 10% interest; 10% = 10/100 = 0.1. This gives us
I=p(0.1)(1) = 0.1p.
Jenny borrows 1000 more than Anson, so her principal is p+1000. Her rate is 8%; 8%=8/100 = 0.08. She invests it for half of a year, or 0.5. Together this gives us:
I=(p+1000)(0.08)(0.5)
= (p+1000)(0.04)
= p*0.04 + 1000*0.04
= 0.04p + 40
Together they earned 740:
0.1p+0.04p+40 = 740
Combine like terms:
0.14p+40 = 740
Subtract 40 from both sides:
0.14p+40-40 = 740-40
0.14p = 700
Divide both sides by 0.14:
0.14p/0.14 = 700/0.14
p = 5000
