bpp mcq bank 34

hello i have a doubt non savings income - 1000 savings income- 5500 what is income tax liability? answer: 500 1000*20/100 200 (5000-1000)=4000*0 0 (5500-4000) 1500*20/100 300 tax liability =500 sir can you please explain why they have deducted 1000? is it because teh rule says that 0% applies to savings incoe where it falls within first 5000 of taxable income? for my solution i did like this 1000*20/100 5000*0/100 500*10/100 which is wrong so my doubt is why they are deducting 1000