Soal SMA · Soal cerita · Kesulitan 4/5
A test has 20 questions. Each correct answer gives 5 points, each wrong answer deducts 2 points, and unanswered gives 0. If a student answered all questions and scored 72 points, how many did they get correct?
- A.16
- B.14
- C.15
- D.17
Kunci jawaban & pembahasan
Jawaban: 16
Let c be correct, w be wrong. c+w=20. 5c-2w=72. Substitute w=20-c: 5c-2(20-c)=72 ⇒ 5c-40+2c=72 ⇒ 7c=112 ⇒ c=16.
Mau penjelasan yang menyesuaikan level anak?
Xinau AI membahas soal langkah demi langkah, menyesuaikan gaya bahasa dengan usia anak, dan menyusun latihan berikutnya berdasarkan jawaban sebelumnya.
Coba gratis 30 hari