1 point 5. In a certain store, small puppets cost $1 cach and large puppets cost $2 each. If the store sold 25 puppets
for a total of $30 dollars, how many small puppets wero sold?
(A) 25
(B) 20
(C) 15
(D) 10
(E)S

(B) 20

Step-by-step explanation:

Let small puppet be represented bys

Let large puppet be represented byl

Total number of puppets expression will be: s+l =25a

The expression for total costs will be : 1$ s + $2l=$30b

Equation a can be written as; s= 25-l c

Use equation c in equation b as

$1( 25-l )+$ 2l = $30

25-l + 2l = 30

25+l =30

l= 30-25 =5

l, large puppets = 5

s, small puppets = 25-5 = 20

Answer choice A is incorrect because 25 is the total number of all puppets

Answer choice C and D are incorrect because the numbers are less that that of small puppets.

the value of v.w= -12.

step-by-step explanation:

we are given three vector r,v and w as:

r = < 5, -5, -2> ; v = < 2, -8, -8> ; w = < -2, 6, -5>

we know that r,v and w could also be represented as:

r=5i-5j-2k

v=2i-8j-8k

and w= -2i+6j-5k

where i,j and k are the unit vectors of x,y and z-axis respectively.

also we know that it has the following property:

i.i=1 ; j.j=1; k.k=1

and i.=j.i=i.k=k.i=j.k=k.j=0

i.e. when we multiply two vectors or we find it's dot product we need to only multiply the components of x coordinates with each other; y with each other and z with each other.

hence, v.w= (2i-8j- -2i+6j-5k)

                  = 2×(-2)+(-8)×(6)+(-8)×(-5)

                  = -4-48+40

                  = -12

hence, v.w= -12

69.64%

step-by-step explanation: