Question

the amount of air present in cylinder when vaccum pump 1/4 of remaing in a cylinder at a time

Answer 1

Hey friend here your answer

ii. Let a be the amount of air initially Amount of air remaining after 1st pump =a –(a/4)=3a/4
Amount of air remaining after 2nd pump= (3a/4) – (1/4)(3a/4)=9a/16
Amount of air remaining after 3rd pump= (9a/16) – (1/4)(9a/16)=27a/64
So the series is like
a,3a/4,9a/4,27a/64……..
Difference Ist and second term=-a/4
Difference between Second and Third term= -3a/16
So difference is not constant
So it is not Arithmetic Progression

I hope it's help you
mark brainiest