The probability any one system works is 0.99
So the probability of any one system failing is 1-0.99 = 0.01, so basically a 1% chance of failure for any one system
Multiply out the value 0.01 with itself four times
0.01*0.01*0.01*0.01 = 0.000 000 01
I'm using spaces to make the number more readable
So the probability of all four systems failing is 0.00000001
Subtract this value from 1 to get
1 - 0.00000001 = 0.99999999
The answer is 0.99999999 which is what we'd expect. The probability of at least one of the systems working is very very close to 1 (aka 100%)
Answer:
i = 75.7°
h = 48.2°
Step-by-step explanation:
==>To find i, use the sine rule for finding angles: sin(A)/a = sin(B)/b
Where,
a = 7.2cm
sin(A) = i
b = 6.5cm
sin(B) = sin(61) = 0.8746
Thus:
sin(A)/7.2 = 0.8746/6.5
Multiply both sides by 7.2
sin(A) = (0.8746*7.2)/6.5
sin(A) = 0.969 (3 s.f)
A = i° = sin^-1(0.969) = 75.7 (3 s.f)
==>To find h, use the Cosine rule for angles:
Cos(C) = (a²+b²-c²)/2ab
cos(C) = h°, a = 4, b = 4.5, c = 3.5
a² = 16
b² = 20.25
c² = 12.25
cos(C) = (16+20.25-12.25)/(2*4*4.5)
cos(C) = 24/36
cos(C) = 0.667 (3 s.f)
C = h° = cos^-1(0.667) = 48.2° (3 s.f)
Answer:
20
Step-by-step explanation:
If 36 boys can conplete a task in 4 hours, then 19.35 boys could do it in 2 and a fourth hours.
You can set up an equation
A fourth of an hour is 15 minutes, so,
36 is to 4 as x is to 2.15, or,
36=4 as X=2.15
Multiply 2.15 by 36 (77.4)
77.4 divided by 4= 19.35.
Of course, you cannot have 19.35 boys, so there must be 20.
Hope this helps!
