B.P.Jha, J.

1. I shall dispose of these three writ petitions, i.e., C.W.J.C. No. 1505 of 1973, C.W.J.C. No. 1506 of 1973 and C.W.J.C. No. 1507 of 1973 by a common judgment, as a common point of law arises for consideration in these writ petitions.

2. The relevant facts are these :

In C.W.J.C. No. 1505 of 1973, the petitioners, M/s. Bhimraj Madan Lal, sold pulses worth Rs. 10,09,040.71 outside the State of Bihar through its arhatia during the period 1968-69. Similarly in C.W.J.C. No. 1506 of 1973, the petitioners, M/s. Bhimraj Madan Lal, during the period 1970-71 sold pulses worth Rs. 22,77,666.44 outside the State of Bihar through its arhatia. In C.W.J.C. No. 1507 of 1973, the petitioners, M/s. Bhimraj Madan Lal, had, during the period 1969-70, sold pulses worth Rs. 16,17,876.85 outside the State of Bihar through its arhatia.

3. The short point for consideration is :

Whether the sales tax authorities can reopen the case in respect of the materials which were already available at their earlier assessment order simply for changing or revising their opinion ? The answer must be given in the negative.

4. These petitioners claimed deduction or exemption on account of sales outsi