3. Seperdelapan dari :
4. The average (arithmetic mean) of three numbers is 20. If one of numbers is replaced by the number 45 then the average of the three numbers is 25. The original number that was replaced is... .
5. Suatui fungsi f(2x + 3) = 3x – 5. Nilai dari f(–5) = ... .
KUNCI JAWABAN
Pembahasan
Baca Juga: Butir Soal OSN Matematika SD MI Disertai Kunci Jawaban dan Pembahasan, Sukses OSN 2022 Part 10
1. Misalkan bilangan I adalah a
Bilangan II adalah b
Maka
a – b = 1
a + b = 2 +
2a = 3
a = 3/2
a – b = 1
3/2 – b = 1
b = 1 – 3/2
b = 1/2