The main reinforcement and secondary reinforcement of RC slab (one way) consists of 20 mm bars with c/c spacing of 150 mm and 16 mm bars with c/c spacing of 200 mm respectively. If it is desired to replace the 20 mm bars by 28 mm and 16 mm bars by 20 mm, then find the ratio of percentage change in spacing of main reinforcement and secondary reinforcement. Given that effective depth of slab is 80 mm and use LSM as per IS456 : 2000.