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2 years ago

Speed, Time, and Di 1 a. An airplane flies with a constant speed of 640 miles per hour. How far can it travel in 2 1/2 hours

Mathematics

1 answer:

Ganezh [65]2 years ago

5 0

Answer:

Step-by-step explanation:

2½ hours × 640 miles/hour = 2½×640 miles = 1,600 miles

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Sanford the elf has been asked to choose toys for a child who wants a baby doll, a jigsaw puzzle, and a stuffed dog. He looks on

zmey [24]

Answer: There are 198 different combinations.

Step-by-step explanation:

To solve this type of problem, first, we need to identify the selections.

We have 3 selections.

Baby doll, Jigsaw puzzle, and a stuffed dog.

Now, we need to count the numbers of options for each case:

Baby doll: 11 options.

Jigsaw Puzzle: 6 options.

Stuffed dog: 3 options.

To find the total number of different combinations, we need to multiply all the numbers of options together, this is:

Combinations = 11*6*3 = 198

There are 198 different combinations.

5 0

2 years ago

A bookcase has two shelves. The top shelf has 10 more than 1/3 the number of books on the bottom shelf. There are 12 books on th

kobusy [5.1K]

Answer: b.14

Step-by-step explanation:

We have two shelves, the top shelf $s_{t}$ and the bottom shelf $s_{b}$ .

Now, firstly we are told the top shelf has 10 more than 1/3 the number of books on the bottom shelf. This can be expressed as:

$s_{t}=10+\frac{1}{3}s_{b}$ (1)

Then, we are told there are 12 books on the bottom shelf:

$s_{b}=12$ (2)

Substituting (2) in (1):

$s_{t}=10+\frac{1}{3}(12)$ (3)

$s_{t}=10+\frac{12}{3}$ (4)

$s_{t}=14$ (5) This is the number of books on the top shelf

Hence, the correct option is b.

6 0

2 years ago

A research team at Cornell University conducted a study showing that approximately 10% of all businessmen who wear ties wear the

LenKa [72]

Answer:

a) The probability that at least 5 ties are too tight is P=0.0432.

b) The probability that at most 12 ties are too tight is P=1.

Step-by-step explanation:

In this problem, we could represent the proabilities of this events with the Binomial distirbution, with parameter p=0.1 and sample size n=20.

a) We can express the probability that at least 5 ties are too tight as:

$P(x\geq5)=1-\sum\limits^4_{k=0} {\frac{n!}{k!(n-k)!} p^k(1-p)^{n-k}}\\\\P(x\geq5)=1-(0.1216+0.2702+0.2852+0.1901+0.0898)\\\\P(x\geq5)=1-0.9568=0.0432$

The probability that at least 5 ties are too tight is P=0.0432.

a) We can express the probability that at most 12 ties are too tight as:

$P(x\leq 12)=\sum\limits^{12}_{k=0} {\frac{n!}{k!(n-k)!} p^k(1-p)^{n-k}}\\\\P(x\leq 12)=0.1216+0.2702+0.2852+0.1901+0.0898+0.0319+0.0089+0.0020+0.0004+0.0001+0.0000+0.0000+0.0000\\\\P(x\leq 12)=1$