81. Restaurants. About 12% of the restaurants in the US are pizzerias, and there are about 70,000 pizzerias in the US. Estimate the total number of restaurants in the United States.

For this case we know that 12% of the restaurants in the Us are pizzerias and there are about 70000 pizzerias in Us. So then we can apply a proportion rule given by:

Where x represent the total of restaurants representing the 100% and if we solve for x we got:

So then there is approximately between 58333 and 58334 restaurants in US with the result obtained.

Step-by-step explanation:

For this case we know that 12% of the restaurants in the Us are pizzerias and there are about 70000 pizzerias in Us. So then we can apply a proportion rule given by:

Where x represent the total of restaurants representing the 100% and if we solve for x we got:

So then there is approximately between 58333 and 58334 restaurants in US with the result obtained.

since the airplane is moving with constant speed then the distance travelled can be calculated by x=u*t

in km/h would be:

x=640*3.5=2.240 km

in m/s would be:

u=640 km/h= 640.000 m/h =640.000/ 3600 m/s =177.8 m/s

t= 3.5 h= 3.5 * 3600 s=12.600 s

then x=u*t= 177.8*12.600= 2.240.280 m

i found two solutions,   n = 2 • ± √3 = ± 3.4641

step-by-step explanation: