Question

Umur Nandan 2 1/2 kali umur Uli.Selisih umur mereka 7 1/2 tahun.Berapa umur mereka masing-masing?.

Answer 1

Misal 
N = Nandan
U= Uli

N = 5/2U
N /U = 5/2
N:U = 5 : 2 = 5a : 2a

N-U = 15/2
5a-2a = 15/2
3a = 15/2
a = 15/6 = 5/2

Nandan= 5a = 5(5/2) = 25/2 = 12  1/2 th
Uli = 2a = 2(5/2) = 10/2 = 5 th

Answer 2

N = nandan
U = uli

N = 2,5 U

N - U = 7,5

N - U = 7,5
2,5 U - U = 7,5
2,5 U - 1U = 7,5
1,5 U = 7,5
1,5U : 1,5 = 7,5 : 1,5
U = 5

N = 2,5 U = 2,5 x 5 = 12,5 th
U = 5 Th