Question

In a filtration plant, water is filtered using layers of
(a) sand and clay
(b) clay and fine gravel
(c) sand and fine gravel
(d) sand, fine gravel and medium gravel

Answer 1

Water is filtered by using layer of sand, fine gravel and medium gravel..

Answer 2

(a) sand and clay

(b) clay and fine gravel✔✔

(c) sand and fine gravel

(d) sand, fine gravel and medium gravel