calculate final volume required to reach 1% solution when 0.2g of sample is predigested with nitric acid 3mL then after 1day, if 1ml sample from this solution is digested in 10ml solution and diluted in 50 mL distilled water.

Answer 1

Either this can't be done or I've misunderstood the question. If the 0.2g sample is pure stuff (and probably it isn't), then the amount in 50 mL = (0.2/3) = 0.06667 g and that is less than 1%.