nomor 8 ya sama pembahasannya

Misalkan :
A = Adi
B = Boni
C = Candra

(A+4) + (B+4) + (C+4) = 52
A + B + C + 12 = 52
A + B + C = 52 - 12
A + B + C = 40

(B-6) : (C-6) = 3 : 1
B - 6 = 3 (C - 6)
B - 6 = 3C - 18
B = 3C - 18 + 6
B = 3C - 12

(A-6) : (B-6) = 1 : 3
3 (A - 6) = B - 6
3A - 18 = B - 6
3A = B - 6 + 18
3A = B + 12
3A = (3C - 12) + 12
3A = 3C
A = C

A + B + C = 40
C + (3C - 12) + C = 40
5C - 12 = 40
5C = 40 + 12
5C = 52
C = 52 ÷ 5
C = 10,4

Jadi umur Candra sekarang adalah 10,4 tahun