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3 years ago

How many different ways can teams of four members be formed from a class of 20?

1 answer:

4 0

Assuming you want to choose 4 people from the class of 20;

Begin by using the combinations formula;

20C4=4845 possibilities

Hope I helped :)

You might be interested in

Write an expression for the phrase.

vitfil [10]

Answer:

9+k-17

Step-by-step explanation:

sum of 9 and k

9+k

minus 17

9+k-17

5 0

3 years ago

A force of 19 newtons is applied on a cart of 2 kilograms, and it experiences a frictional force of 1.7 newtons. What is the acc

arsen [322]

Answer:

option A

a = 8.65 m/s²

Step-by-step explanation:

Given that,

force applied on a cart (forward direction) = 19N

frictional force experience by cart (backward direction) = 1.7N

mass of the cart = 2 kg

Frictional force always opposes applied force, so the Resultant force on the cart would have to be 19N - 1.7N.

Formula to use

Resultant force = ma

plug values in the formula

19 - 1.7 = 2(a)

17.3 = 2(a)

a = 8.65 m/s²

so the acceleration of the cart is 8.65m/s²

4 0

3 years ago

Read 2 more answers

Use triangle ABC drawn below & only the sides labeled. Find the side of length AB in terms of side a, side b & angle C o

Brrunno [24]

Answer:

$AB = \sqrt{a^2 + b^2-2abCos\ C}$

Step-by-step explanation:

Given:

The above triangle

Required

Solve for AB in terms of a, b and angle C

Considering right angled triangle BOC where O is the point between b-x and x

From BOC, we have that:

$Sin\ C = \frac{h}{a}$

Make h the subject:

$h = aSin\ C$

Also, in BOC (Using Pythagoras)

$a^2 = h^2 + x^2$

Make $x^2$ the subject

$x^2 = a^2 - h^2$

Substitute $aSin\ C$ for h

$x^2 = a^2 - h^2$ becomes

$x^2 = a^2 - (aSin\ C)^2$

$x^2 = a^2 - a^2Sin^2\ C$

Factorize

$x^2 = a^2 (1 - Sin^2\ C)$

In trigonometry:

$Cos^2C = 1-Sin^2C$

So, we have that:

$x^2 = a^2 Cos^2\ C$

Take square roots of both sides

$x= aCos\ C$

In triangle BOA, applying Pythagoras theorem, we have that:

$AB^2 = h^2 + (b-x)^2$

Open bracket

$AB^2 = h^2 + b^2-2bx+x^2$

Substitute $x= aCos\ C$ and $h = aSin\ C$ in $AB^2 = h^2 + b^2-2bx+x^2$

$AB^2 = h^2 + b^2-2bx+x^2$

$AB^2 = (aSin\ C)^2 + b^2-2b(aCos\ C)+(aCos\ C)^2$

Open Bracket

$AB^2 = a^2Sin^2\ C + b^2-2abCos\ C+a^2Cos^2\ C$

Reorder

$AB^2 = a^2Sin^2\ C +a^2Cos^2\ C + b^2-2abCos\ C$

Factorize:

$AB^2 = a^2(Sin^2\ C +Cos^2\ C) + b^2-2abCos\ C$

In trigonometry:

$Sin^2C + Cos^2 = 1$

So, we have that:

$AB^2 = a^2 * 1 + b^2-2abCos\ C$

$AB^2 = a^2 + b^2-2abCos\ C$

Take square roots of both sides

$AB = \sqrt{a^2 + b^2-2abCos\ C}$

6 0

3 years ago

14x=x^2-15<br><br> find the value of x

hram777 [196]

Answer: $x=-1, 15$

Step-by-step explanation:

$x^2 -14x-15=0\\\\(x-15)(x+1)=0\\\\x=-1, 15$

5 0

2 years ago

Is 2.81 an irrational number

nekit [7.7K]

Answer:

No.

Step-by-step explanation:

It can be written as 2 81/100 or 281/100 so it is not irrational. An irrational number is a number that cannot be written as a ratio of two numbers

5 0

3 years ago

Read 2 more answers