Answer:
52 cards:
26 red and 26 black
P(R) = probability of picking a red card
P(B) = probability of picking a black card
P(R) = P(B) = ¹/₂
If with replacement:
P(R∩B) = (¹/₂)(¹/₂) = ¹/₄
If without replacement:
P(R∩B) = (¹/₂)(²⁶/₅₁) = ¹³/₅₁
8 Balls:
3 red and 5 white
P(R) = probability of picking a red ball
P(W) = probability of picking a white ball
P(R) = ³/₈
P(W) = ⁵/₈
If with replacement:
P(R∩W) ∪ P(W∩R) = (³/₈)(⁵/₈) + (⁵/₈)(³/₈)
= ¹⁵/₆₄ + ¹⁵/₆₄
= ³⁰/₆₄
= ¹⁵/₃₂
If without replacement:
P(R∩W) ∪ P(W∩R) = (³/₈)(⁵/₇) + (⁵/₈)(³/₇)
= ¹⁵/₄₂ + ¹⁵/₄₂
= ³⁰/₄₂
= ⁵/₇
Answer:
2 miles
Step-by-step explanation:
Their combined speed (speed of closure) is 80 mph + 40 mph = 120 mph.
120 mi/h = 120 mi/(60 min) = 2 mi/min
The distance between the trains at the 1-minute mark is ...
(1 min) · (2 mi/min) = 2 mi
They were warned when two miles apart.
Golden retrievers: 12/32
poodles: 20/32
does it need to be simplified?
<em>Answer:</em>
<em>7/78 - 35/78i</em>
<em>Step-by-step explanation:</em>
<em>A complex number is a real number, an imaginary number or a number with both real and imaginary number. Its standard form is:
</em>
<em>a + bi
</em>
<em>
</em>
<em>For the expression, 7/ 3-15i
</em>
<em>
</em>
<em>(7/ 3-15i) (3+15i)
</em>
<em>21 - 105i / (234)
</em>
<em>7/78 - 35/78i
</em>
