nios std x business studies Ch 8 postal and courier services nios std x Business studies Ch 7 communication services nios std X business studies Ch 6 Warehousing nios std x social science Ch 12 agriculture nios Std X Social Science Ch 11biodiversity NIOS STD X Economics Ch 20 sectoral aspets NIOS STD X 10th Business Studies Ch 5 transport services NIOS Std X, 10th Business Studies Ch 4 cooperative society NIOS Business Studies Std X Ch 3 Sole proprietorship Calculation of arithmetic mean NIOS STD X Economics Chapter 17 & 18 Collection, Presentation and analysis of Data