Please solve the following and show work. Thank you

Find out the one-time principal

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1. You are leaving the USA to become the president of a foreign company for the next 20 years. You sign an agreement with the METLIFE insurance Company to pay your mother a year-end annuity A= $50,000 for the next 20 years at a RATE OF RETURN i =8%. What one-time principal "P" must be paid to MELIFE at 1=0 for the 20-years annuity? Show your calculations