PENDEKATAN MATEMATIKA REALISTIK UNTUK MEMBANGUN KEMAMPUAN PEMECAHAN MASALAH MATEMATIS SISWA KELAS XI IPS PADA MATERI PELUANG [REALISTIC MATHEMATICS EDUCATION IN BUILDING THE MATHEMATICS PROBLEM-SOLVING ABILITIES OF GRADE 11 SOCIAL SCIENCE TRACK STUDENTS STUDYING PROBABILITY] - Tambunan, Susiana Juseria (Universitas Pelita Harapan, 2019)