Perbandingan banyaknya siswa perempuan dan siswa laki-laki kelas IX adalah 7:3. siswa yang lulus ujian Matematika sebanyak 40%. Apabila terdapat 30 siswa yang tidak lulus ujian, tentukan banyaknya siswa perempuan dan siswa laki-laki dalam kelas tersebut.

<p>Jawaban yang tepat adalah&nbsp;</p><ul><li>Perempuan = 35 Siswa</li><li>Laki-laki = 15 siswa</li></ul><p>&nbsp;</p><p>Pembahasan :</p><p><strong>Menentukan banyak siswa dalam satu kelas</strong></p><p>Misalkan jumlah siswa = n</p><p>Siswa yang tidak lulus = 100% - 40% = 60%</p><p>60% x n = 30</p><p>6/10 x n = 30</p><p>n = 30 x 10/6</p><p>&nbsp; &nbsp; = 300/6</p><p>&nbsp; &nbsp; = 50 siswa</p><p>Jumlah siswa keseluruhan adalah 50 siswa</p><p>&nbsp;</p><p><strong>Mencari Jumlah siswa laki-laki dan perempuan&nbsp;</strong></p><p>Perempuan : Laki-laki = 7 : 3</p><p>Jumlah siswa perempuan = 7/(7 + 3) x 50</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= 7/10 x 50</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= 35 Siswa</p><p>Jumlah Siswa laki-laki = 3/(7 + 3) x 50</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; = 3/10 x 50</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; = 15 siswa</p>