P varies directly with Q and inversely with R. P=9, when Q=3 and R=4. How do you find Q when P=1 and R=1/2?

1 Answer
Jan 7, 2018

Q=1/24Q=124

Explanation:

If PP varies directly with QQ and inversely with RR then
color(white)("XXX")(P * R)/Q=kXXXPRQ=k for some constant kk

If P=9, Q=3, and R=4P=9,Q=3,andR=4 then
color(white)("XXX")(9 * 4)/3=kcolor(white)("xx")rarrcolor(white)("xx")k=12XXX943=kxxxxk=12

So when P=1P=1 and R=1/2R=12
color(white)("XXX")(1 * 1/2)/Q=12XXX112Q=12

color(white)("XXX")1/2=12QXXX12=12Q

color(white)("XXX")Q=1/24XXXQ=124