Susan invests twice as much money at 7.5% as she does at 6%. if her total interest after a year is $840 how much does she have invested at each rate?

Let x be the amount invested at 6%

840 = 0.06x + 0.075(2x)
840 = 0.06x + 0.15x
840 = 0.21x
x = 840/0.21
x = 4000

Therefore, she invests $4000 at 6% and $8000 at 7.5%

answer: it's d

step-by-step explanation:

answer:   28.56 feet (approx)

step-by-step explanation:

since, triangle abc has measure of angle c equal to 55 degrees, measure of angle abc equal to 90 degrees, and length of bc equal to 20 feet.

we have to find out the measurement of segment ab.

therefore, tan 55° =

but bc = 20 feet.

⇒ tan 55 ° =  

⇒ ab = 20 × tan 55 °

⇒ ab = 20 × 1.42814800674

⇒ ab = 28.5629601348   ≈ 28.56 feet