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annuities question - equations of value
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these are the steps i'd follow: $200 today times (1.04)^10 = cost in year 10.  the 6 deposits of $20 will be one time value calculation with a resulting year 7 final value. you then must apply 10% for 3 years (1.1)^3 to get the 10th year result.  you now have the shortfall. divide that by the same (1.1)^3 to shift the present value to start of year 7. (this step might confuse you?) you are left with a problem needing 3 same deposits, a known rate, and desired fv. solve from there.  (also, welcome from quant.se. this site doesn't support latex, so i edited the image above.)
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