You

a gas occupies 40 liters at a pressure of 10.0 kpa. what is the volume when the pressure is increased to 150 kpa?

solution is here,

initial volume(V1)=40 litres

initial pressure(P1)=10 Kpa

final volume(V2)=?

final pressure(P2)=150 Kpa

at constant temperature, from Boyle's law,

P1V1=P2V2

or, 10×40 =150 × V2

or, 400= 150×V2

or, V2= 400/150

or, V2=2.67 litres

resonant frequency

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.