Question

Can someone that's very good at math please help me?

35: Problem Solving:You deposit $2000 in an account that earns simple interest at an annual rate of 4%.How long must you leave the money in the account to earn $500 in interest?

36: Problem Solving: A flight averages 460 miles per hour.The return flight averages 500 miles per hour due to a tailwind.The total flying time is 4.8 hours.How long is each flight?​

Answer 1

35 :

t = 6.25 years

(about 6 years 3 months)

Equation:

t = (1/r)(A/P - 1)

Calculation:

First, converting R percent to r a decimal

r = R/100 = 4%/100 = 0.04 per year,

then, solving our equation

t = (1/0.04)((2500/2000) - 1) = 6.25

t = 6.25 years

The time required to get a total amount, principal plus interest, of $2,500.00 from simple interest on a principal of $2,000.00 at an interest rate of 4% per year is 6.25 years (about 6 years 3 months).

36:

The two distances are the same (out and back), so set them equal.

That is done by having a (rate)(time) equal a (rate)(time).

One time is “x” and the other is “4.8-x.”

One rate is 460 and the other is 500.

460 x = 500 (4.8 -x)

460 x = 2400 - 500x

900 x = 2400

x = 2.5 hours for the slower plane.

4.8- x = 2.3 hours for the faster plane.