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3 years ago

PLEASE TRY YOUR BEST ON THESE

Mathematics

1 answer:

iris [78.8K]3 years ago

4 0

Answer:

hey i can help if you want it

Step-by-step explanation:

You might be interested in

67 times a number minus 65 is equal to -4 less than the number

sashaice [31]

Answer:

Translation is 67x-65=x-4, you can use any variable for the number.

Step-by-step explanation:

7 0

3 years ago

Tim must read 2 books from a list of 7 recommended books for his summer reading program. In how many different ways can Tim choo

Marianna [84]

There are 21 ways Tim choose 2 books from the 7 recommended book

Solution:

Given that Tim must read 2 books from a list of 7 recommended books for his summer reading program

To find: different ways can Tim choose 2 books from the 7 recommended books

This is a combination problem

A combination is a selection of all or part of a set of objects, without regard to the order in which objects are selected

The formula for combinations is:

$n C_{r}=\frac{n !}{r !(n-r) !}$

where n represents the number of items, and r represents the number of items being chosen at a time

Here we have to choose 2 books from 7 books

Therefore, n = 7 and r = 2

Substituting values in above formula, we get

$\begin{aligned}&7 C_{2}=\frac{7 !}{2 !(7-2) !}\\\\&7 C_{2}=\frac{7 !}{2 ! \times 5 !}\end{aligned}$

For a number n, the factorial of n can be written as,

$n !=n \times(n-1) \times(n-2) \dots \dots \times 2 \times 1$

Therefore, we get

$7 C_{2}=\frac{7 \times 6 \times 5 \times 4 \times 3 \times 2 \times 1}{2 \times 1 \times 5 \times 4 \times 3 \times 2 \times 1}\\\\7C_2 = 7 \times 3 = 21$

Thus there are 21 ways Tim choose 2 books from the 7 recommended book

7 0

3 years ago

A culture of yeast doubles in size every four hours. If the yeast population is estimated to be three million now, what will it

Bess [88]

It doubles every 4 hours, so after 24 hours there will be 6 doublings.
2^6 = 64
So, the population will be (3,000,000 * 64) or 192,000,000 in 24 hours.
The answer is B.

4 0

4 years ago

Read 2 more answers

The average value of two positive numbers is 30% less than one of the two numbers. By which percentage is average value bigger t

Viefleur [7K]

Answer:

75% bigger

Step-by-step explanation:

Let the first number be x and the second be y.

So:

$Average = \frac{x + y}{2}$