Question

SOAL LATIHAN............

Answer 1

Misalkan jumlah kelereng mula-mula:
A = a buah
W = w buah
Babak Pertama
Kelereng A = a - 1/3 a = 2/3 a
Kelereng W = w + 1/3 a

Babak kedua:
Kelereng W = 1/2 ( w + 1/3 a) = 1/2w + 1/6a
Kelereng A = 2/3a + 1/2(w + 1/3 a)
                     = 2/3 a + 1/2w + 1/6a
                     = 5/6 a + 1/2 w

Babak ketiga
Kelereng A = 5/6 a + 1/2 w - 5
Kelereng W = 1/2w + 1/6 a + 5

Keadaan akhir:
Kelereng A
5/6a + 1/2w - 5 = 15
5/6 a + 1/2w = 20                      (kali 6)
5a + 3w = 120 ..................(1)

Kelereng W
1/2w + 1/6a + 5 = 13
1/6a + 1/2w = 8                    (kali 6)
a + 3w = 48 ......................(2)

Persamaan (1) dan (2)

5a + 3w = 120
  a + 3w = 48    -   
4a        = 72
          a = 18
         w = 10

Jadi selisih kelereng mereka mula-mula : 18 - 10 = 8 buah