Seorang pemborong akan menyelesaikan pembangunan sebuah jembatan selama 96 hari dengan 40 orang pekerja. Setelah pembangunan berjalan selama 12 hari, ada 8 orang pekerja yang mengundurkan diri dan tidak kembali bekerja lagi, maka berapa lama tambahan waktu yang diperlukan?

<p><strong>Jumlah pekerja &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Waktu Pengerjaan</strong></p><p>40 pekerja &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;96 hari</p><p>40 Pekerja &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;12 hari</p><p>40 - 8 = 32 pekerja &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;a hari</p><p>&nbsp;</p><p>40 x 96 = (40 x 12) + ( 32 x a)</p><p>3.840 = 480 + 32a</p><p>3.840 - 480 = 32a</p><p>3.360 = 32a</p><p>a = 3.360 : 32</p><p>a = 105 hari</p><p>&nbsp;</p><p>Tambahan waktu = 105 - (96 - 12)</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= 105 - 84</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= 21 hari</p><p>Jawaban : C</p>