\text { The extremities of an } 8 ~m \text { long straight bamboo pole rest on two smooth pegs } P \text { and } Q \text { in the same } \text { horizontal line. A heavy load hangs from a point } R \text { of the pole. If } P R=3 R Q \text { and the pressure at } Q \text { be } 325 \text { gm-wt more than that of } P \text {, the weight of the load is- }