6 pennies, 12 nickels, 8 dimes, 4 quarters = 30 coins
a) add the probability for drawing a dime and drawing a quarter together:
12/30 + 4/30 = 16/30 = 8/15
The probability is 8/15 or 53%
b) multiply the probability for drawing a penny and drawing a nickel:
6/30 x 12/30 = 72/900 = 2/25
The probability is 2/25 or 8%
c) multiply the probability for drawing quarters but take away one of the total coins and the amount of quarters each time:
4/30 x 3/29 x 2/28 = 24/24360 = 1/1015
The probability is 1/1015 or 0.099%
Answer:
tan(2u)=[4sqrt(21)]/[17]
Step-by-step explanation:
Let u=arcsin(0.4)
tan(2u)=sin(2u)/cos(2u)
tan(2u)=[2sin(u)cos(u)]/[cos^2(u)-sin^2(u)]
If u=arcsin(0.4), then sin(u)=0.4
By the Pythagorean Identity, cos^2(u)+sin^2(u)=1, we have cos^2(u)=1-sin^2(u)=1-(0.4)^2=1-0.16=0.84.
This also implies cos(u)=sqrt(0.84) since cosine is positive.
Plug in values:
tan(2u)=[2(0.4)(sqrt(0.84)]/[0.84-0.16]
tan(2u)=[2(0.4)(sqrt(0.84)]/[0.68]
tan(2u)=[(0.4)(sqrt(0.84)]/[0.34]
tan(2u)=[(40)(sqrt(0.84)]/[34]
tan(2u)=[(20)(sqrt(0.84)]/[17]
Note:
0.84=0.04(21)
So the principal square root of 0.04 is 0.2
Sqrt(0.84)=0.2sqrt(21).
tan(2u)=[(20)(0.2)(sqrt(21)]/[17]
tan(2u)=[(20)(2)sqrt(21)]/[170]
tan(2u)=[(2)(2)sqrt(21)]/[17]
tan(2u)=[4sqrt(21)]/[17]
Answer:45 * t = 2.5 * (1-t)...the equation will have one solution.
Step-by-step explanation:
For this case, the first thing you should know is:
d: v * t
Where,
d: distance
v: speed
t: time
To go to school by bus we have:
d = 45 * t
To return from school we have:
d = 2.5 * (1-t)
how the distance is the same:45 * t = 2.5 * (1-t)
Step-by-step explanation:
Given that,
The length of a ladder, H = 20 feet
The height of the wall, h = 15 ft
We know that,
h is perpendicular and H is hypotenuse
So,
Now using Pythagoras theoerm,
Hence, the angle made by the ladder and the ground is 48.59° and the ladder is 13.2 feet from the wall on the ground.
