The occurrence of casting defect ‘rat tail’ is possible because of
1. Soft ramming of sand
2. Continuous large flat surface on the mould
3. Excessive hardness of the mould
Which of the above reasons are correct?
(a) 1 and 2 only (b) 2 and 3 only
(c) 1 and 3 only (d) 1, 2 and 3