度分秒计算~谢.

题目

度分秒计算~谢.
60°31'43''x2-45°13'30''/3+18°45'48''
虽然两位都很好。可是最后的答案应该是124°46'44''...

答案

1°=60'
1'=60''
60°31'43''x2-45°13'30''/3+18°45'48''
=120°62'86''-15°4'30''+18°45'48''
=123°103'104''
=124°44'44