Answer:
Step-by-step explanation:
This is one of the more interesting motion problems I've seen. I like it! If Kelly is driving north (straight up) for 9 miles, then turns east (right) and drives for 12 miles, what we have there are 2 sides of a right triangle. The hypotenuse is created by Brenda's trip, which originated from the same starting point as Kelly and went straight to the destination, no turns. We need the distance formula to solve this problem, so that means we need to find the distance that Brenda drove. Using Pythagorean's Theorem:
and
and
so
c = 15.
Brenda drove 15 miles. Now we can fill in a table with the info:
d = r x t
Kelly 12+9 42 t
Brenda 15 45 t
Because they both left at the same time, t represents that same time, whatever that time is. That's our unknown.
If d = rt, then for Kelly:
21 = 42t
For Brenda
15 = 45t
Solve Kelly's equation for t to get
t = 1/2 hr or 30 minutes
Solve Brenda's equations for t to get
t = 1/3 hr or 20 minutes
That means that Brenda arrived at the destination 10 minutes sooner than Kelly.
Answer:
the second one -9/4 divided (-2/3)
Step-by-step explanation:
Answer:
139/150
Step-by-step explanation:
Let's make a list of the perfect squares.
1 4 9 16 25 36 49 64 81 100 121 144
The probability that one of these is drawn is 12/150 = 4/50 = 2/25
Take out 1. So that means there are 11 perfect squares.
11/150 are your chances of getting a perfect square.
1 - 11/150 = 139/150 that you will not get a perfect square.
I would have included 1 in the perfect squares, but the question says not to so you can't.
If the question did not mean that 1 should be excluded, then the answer is 23/25