Explanation:

Step I : Salt Price of 1 kg of combination= Rs. 9.24
obtain= 10%
C.P of 1 kg of combination =[ (100) / (100+10)x9.24 ] = Rs. 8.40
Salts price = Rs. 8.40/-
Step (ii) By the rule of allegation
vi. C.P of  1 kg of salt of  I kind (p) = 900
vii. C.P of  1 kg of salt of  II kind (p) = 700
viii.    Mean salt price (p) = 840
ix.    d – m = 900 – 840 = 60
x.    m – c = 840 – 700 = 140
Needed ratio = 140 : 60 = 7 : 3
Step (iii) Let (x) kg of salt of I kind be combined with 27 kg of II kind
7 : 3 = x : 27 => 7/3 = (x/27) => x = (7/3)*(27)= 63 kg.