please answer all parts (a-d)

insty a semiminua comverion if a, the matietix is 15 yeass? b. the maturity is 76 years? 6. the muturly is 6 y years? id ese matuify is 80 years? (Round io me nearest cersi) insty a semiminua comverion if a, the matietix is 15 yeass? b. the maturity is 76 years? 6. the muturly is 6 y years? id ese matuify is 80 years? (Round io me nearest cersi)