Abell rings every 2 hours, a second bell rings every 3 hours, and a third bell rings every 4 hours. if all 3 bells rind at 9: 00am., at what time will all 3 bells next ring?

9:00 P.M.

Step-by-step explanation:

All 3 bells ring at 9AM

1st bell: every 2 hours:

9AM, 11AM, 1PM, 3PM, 5PM, 7PM, 9PM

2nd bell: very 3 hours:

9AM, 12AM, 3PM, 6PM, 9PM

3rd bell: every 4 hours:

9AM, 1PM, 5PM,  9PM

So All 3 bells will ring at 9PM again

answer: huh

step-by-step explanation:

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