3 x
---------= --------- ---------
15 180
15x=540
----- ------= 36 students.
15 15
Steps: Cross multiply to get 15x and 540. Divide both numbers by 15, then you found what x equals, which is the answer.
The measure of an arc refers to the arc length divided by the radius of the circle. The arc measure equals the corresponding central angle measure, in radians. That's why radians are natural: a central angle of one radian will span an arc exactly one radius long.
Is the correct
Answer:
165 different teams of 3 students can be formed for competitions
Step-by-step explanation:
Combinations of m elements taken from n in n (m≥n) are called all possible groupings that can be made with the m elements so that:
- Not all items fit
- No matter the order
- Elements are not repeated
That is, a combination is an arrangement of elements where the place or position they occupy within the arrangement does not matter. In a combination it is interesting to form groups and their content.
To calculate the number of combinations, the following expression is applied:
It indicates the combinations of m objects taken from among n objects, where the term "n!" is called "factorial of n" and is the multiplication of all the numbers that go from "n" to 1.
In this case:
Replacing:
Solving:
being:
- 3!=3*2*1=6
- 8!=8*7*6*5*4*3*2*1=40,320
- 11!=39,916,800
So:
C= 165
<u><em>165 different teams of 3 students can be formed for competitions</em></u>
<span>4.5 g
56.25 g
Since the only type of measurement mentioned in this question is weight or mass, I'll assume that the percentage concentration is % m/m (mass/mass). For that type of concentration measurement, simply multiple the percentage by the total mass to get the mass of the desired substance. So
150 g * 3% = 150 g * 0.03 = 4.5g
For the amount of 8% solution with the same amount of dry substance, there's 2 ways of calculating the mass of solution.
First, use the ratio of percentages, multiplied by the mass of the original solution to get the desired amount of new solution:
3/8 * 150 g = 56.35 g
Or calculate it from scratch, like
4.5/X = 8/100
450/X = 8
450 = 8X
56.25 = X
In both cases, the result is that you desire 56.25 grams of 8% solution.</span>
