Let $X$ be the random variable denoting the number of girls that are born. Then $X$ has a binomial distribution on $n=125$ babies and probability of getting a girl $p=0.5$ . The probability we want is

$\mathbb P(X\ge60)=\displaystyle\sum_{x=60}^{125}\binom{125}x0.5^{125-x}0.5^x\approx0.704=70.4\%$

7 0

3 years ago

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A tourist purchases a car in england and ships it home to the united states. the car sticker advertised that the car's fuel cons

Valentin [98]

<u>Solution-</u>

Fuel consumption rate = 40 miles per UK gallon (As the car is manufactured in UK)

1 UK gallon = 4.5459631 lit

1 US gallon = 3.7853060 lit

$\therefore \frac{1 \ UK \ gallon}{1 \ US \ gallon} = \frac{4.5459631}{3.7853060} = 1.2009499$

$\Rightarrow 1 \ UK \ gallon = 1.2009499 \ US \ gallon$

As the fuel consumption rate = 40 miles per gallon

⇒ You need 1 UK gallon of fuel to go 40 miles

⇒ You need 1.2009499 US gallon of fuel to go 40 miles

Or you can say that, to go 40 miles you need 1.2009499 US gallon of fuel

⇒ To go 1 mile you will need $\frac{1.2009499}{40} = 0.0300237$

⇒ To go 738 miles you will need 0.0300237×738 = 22.1574906 US gallon of fuel

∴ 22.1574906 gallon of fuel is actually required.

∴ But, what she thinks will require is $\frac{738}{40} = 18.45 gallons$ (As she calculated using UK gallons)

6 0

3 years ago

If I can paint a wall in 20 min and my friend can paint a wall in 30 min. How many minutes would it take for us to paint a wall

ra1l [238]

Answer: $12\ \text{min}$

Step-by-step explanation:

Given

It takes 20 min and 30 min for a person and his friend to paint a wall individually i.e.

In 1 min they cover $\frac{1}{20}$ part and $\frac{1}{30}$ part of wall respectively.

If the work together, 1 minute work is

$\Rightarrow \dfrac{1}{20}+\dfrac{1}{30}\\\\\Rightarrow \dfrac{3+2}{60}\\\\\Rightarrow \dfrac{5}{60}$

Time required will be reciprocal of it

$\Rightarrow \dfrac{60}{5}=12\ \text{min}$

3 0

3 years ago