a group of 4 pupils can take 2 weeks to do a certain job. how long will 12 pupils take to complete the job if they work at the same rate

6 weeks

Step-by-step explanation:

Set up a proportion where x is the amount of time with 12 pupils:

=

Cross multiply and solve for x:

4x = 24

x = 6

So, it will take 12 pupils 6 weeks to complete the job.

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

what's that