Given, volume of the frustum =28.49L=28.49×1000 cm3 [∵1L=1000 cm3]
=28490 cm3
Radius of the top (r1)=28 cm
Radius of the bottom (r2)=21 cm
Let height of the bucket = h cm
Now, volume of the bucket
=13πh(r21+r22+r1r2)=28490 [given]
⇒13×227×h(282+212+28×21)=28490⇒h(784+441+588)=28490×3×722⇒1813h=1295×21∴h=1295×211813=271951813=15 cm