This is common with scanned copies. Try to find a “text-based” PDF (not scanned images) if any student re-typed it. Alternatively, buy a second-hand physical copy from Poth.lk or Sadeepa Book Shop .
" (ව්යාපාර අධ්යයනය), these are available through Sankha Books for both Part 1 and Part 2. Official Digital Resources jagath bandaranayake business studies book pdf sinhala 2021