The number of boys is 3/5 of the number of girls. If there are 120 children all together, how many boys are there? PLEASE HELP ME

72 boys

Step-by-step explanation:

120 * .60. That's how you solve it! Hope it helps!

Further explanation:

To get .60, you divide 3 by 5 which is .60

Then you multiply 120 times .60 and you'll get 72 which is 72 boys

Bonus: 120 - 72 = 48 girls!

There are 45 boys.

Step-by-step explanation:

The best way to easily solvethis is by making equations, see below.

Now we can subtract the secons equation from the first.

I'm also goong to multiply the equatipn by 5 to remove the fraction.

Now simplify

Now we found out there are 75 girls. Now we insert this into our second equation to find how many boys there are.

Now we know there are 45 boys.

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

true

step-by-step explanation: