Jawabanmu

2014-09-06T23:56:18+07:00
0.5x3600+20x60+90= 1800+1200+90=3090sekon
2014-09-07T00:00:56+07:00
0,5 jam = 1800 sekon (0,5 x 3600)
20 menit = 1200 sekon (20 x 60)
90 sekon

1800 + 1200 + 90 = 3090 sekon
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