Soal Kompetisi Matematika

1. Pada Gambar disamping, berapakah nilai dari x?

(A) 20

(B) 80

(C) 100

(D) 120

(E) 60

2. Selama seminggu, Pasar modal Toronto Stock Exchange mencatat peningkatan dan penurunan sebagai berikut :

Monday –150                        Thursday +182

Tuesday +106                       Friday – 210

Wednesday –47

Berapa perubahan dalam satu minggu tersebut?

(A) menurun 119 point

(B) meningkat 119 point

(C) meningkat 91 point

(D) menurun 91 point

(E) meningkat 695 point

3. Jika x * y = x + y², maka 2 *3 = ...

(A) 8

(B) 25

(C) 11

(D) 13

(E) 7

4. Diantara penyataan berikut, berapa banyak yang benar?

(i) 20% dari 40 = 8     (ii) 2³ = 8   (iii) 7 – 3 × 2 = 8    (iv) 3² – 1² = 8    (v) 2(6 – 4)² = 8

(A) 1

(B) 2

(C) 3

(D) 4

(E) 5

5. Karl had his salary reduced by 10%. He was later promoted and his salary was increased by 10%. If his original salary was $ 20 000, what is his present salary?

(A) $16 200

(B) $19 800

(C) $20 000

(D) $20 500

(E) $24 000