Let $s$ be the speed of the plane in still air, and $w$ the wind speed. A tailwind blows in the same direction as the plane, so for the first leg of the trip, we have

$158\,\dfrac{\rm km}{\rm h}=s+w$

For the return trip, the wind would blow in the opposite direction:

$112\,\dfrac{\rm km}{\rm h}=s-w$

Solve this system and you'll find $s=135\,\dfrac{\rm km}{\rm h}$ and $w=23\,\dfrac{\rm km}{\rm h}$ .

7 0

3 years ago

Benson purchased a $1,800 certificate of deposit that earns simple annual interest. At the end of 1 year, the certificate was wo

Makovka662 [10]

Answer:

Step-by-step explanation:

Step one:

given data

principal P= $1800

time t= 1 year

Final amount A=1857.60

rate r=?

Step two:

we are expected to solve for the rate, let assume the investment is a simple interest type.

A=P(1+rt)

solve for r we can substitute our data

1857.60=1800(1+r*1)

1857.60=1800+1800r

1857.60-1800=1800r

57.6=1800r

r=57.6/1800

r=0.032

0.032*100= 3.2%

<u>This shows that the rate is 3.2%</u>

5 0

3 years ago