A rectangular tank measuring 5 m × 4.5 m × 2.1 m is dug in the centre of the field measuring 13.5 m × 2.5. The earth dug out is spread evenly over the remaining portion of a field. How much is the level of the field raised ? Choose the correct choice from the following choices:
A) 4.0 m
B) 4.1 m
C) 4.2 m
D) 4.3 m
E) none of these

Rationale: area of the field = 13.5 × 2.5 = 33.75 m 2 area covered by the rectangular tank = 5 × 4.5 = 22.50 m 2 area of the field on which the earth dug out is to be spread = 33.75 – 22.50 = 11.25 m 2 let the required height be h . then , 11.25 × h = 5 × 4.5 × 2.1 or h = 4.2 m answer c
Answer: C