Chromium from a mine tailing was determined by atomic absorption spectrophotometry. Ten mL of unknown sample was diluted

[answerhappygod]

Chromium from a mine tailing was determined by atomic absorption
spectrophotometry. Ten mL of unknown sample was diluted to 50 mL
gave an Absorbance of 0.201. Another 10 mL of the unknown was added
with 1 mL of standard 122 ppm Cr and diluted to 50 mL. This
solution gave an absorbance of 0.292. What is the Cr concentration
in the sample?
Note:
1. Please help me asap, I only have less than 30 minutes
to review.
2. Auto like for correct answer. Thank you!
3. Do not answer if you do not know.