Answer:

Step-by-step explanation:
Let
Vco------------------- >Volume cone
Vcy------------------ >Volume cylinder
r= 8mm
hco----------- > height of cone=18 mm
hcy------------ > height of cylinder =54-18=36 mm
then
Vco=π*r² *hco/3--------- > π*8² *18/3=π*384 mm³
Vcy=π*r² *hcy--------- > π*8² *36=π*2304 mm³
the total cubic millimeters of sand=Vco+Vcy=π*384+π*2304=π*2688
if 10π cubic millimeters --------------------- > 1 seg
π*2688--------------------------------- X
X=π*2688/10π=268.8 seg
the answer is 268.8 seg
k=-36
Step-by-step explanation:
x inversely proportional to y
x=1k/y
where k = constant
x= -3, y= 12, k = ?
-3=k/12
k = -3 × 12
k = -36
Subtract what is to the right of the equal sign form both side of the equation but any way the answer is 0