Let x be the time she ran and y be the time she walked
then distance ran = 25x and distance walked = 5y
so 15x + 5y = 42
and x + y = 4
* second equn. by -5:-
-5x - 5y = -20
add this to the first equn:0
10x = 22
x = 2.2
distance she ran = 2.2 * 15 = 33 km
Answer:
a) 137.9°
b) 12.2° (please refer to explanation because I didn't know what to round to)
Step-by-step explanation:
1a) A supplementary angle will equal 180°, so you must subtract 42.1 from 180
180-42.1 = 137.9
1b) A complementary angle will equal 90°, so you need to use the expression given and add an x for the other part of 90°
8x-20+x = 90
9x-20=90
9x=110
x=12.2
Answer:
1.2 gallons
Step-by-step explanation:
We assume that each room is rectangular with four walls and no doors. If the dimensions are length l, by width w with height h, then there are two walls with area l*h and two walls with w*h.
The total area of the room is thus: 2lh + 2wh = 2h(l+w).
l = 12ft, w = 12ft, h = 10ft (all given)
Area of walls = 2h(l+w) = 2*10(12+12)
Area = 2*10*24 = 480 square feet
Each gallon of paint covers 400 square feet. So, you will need to buy
480 / 400 = 1.2 gallons
You will need to buy 2 gallons
Answer:
The expected value of betting $500 on red is $463.7.
Step-by-step explanation:
There is not a fair game. This can be demostrated by the expected value of betting a sum of money on red, for example.
The expected value is calculated as:
being G the profit of each possible result.
If we bet $500, the possible outcomes are:
- <em>Winning</em>. We get G_w=$1,000. This happens when the roulette's ball falls in a red place. The probability of this can be calculated dividing the red slots (half of 36) by the total slots (38) of the roulette:
- <em>Losing</em>. We get G_l=$0. This happens when the ball does not fall in a red place. The probability of this is the complementary of winning, so we have:
Then, we can calculate the expected value as:
We expect to win $463.7 for every $500 we bet on red, so we are losing in average $36.3 per $500 bet.
Answer:
60
Step-by-step explanation:
5²= 10
10x3=30
90-30=60
