S.P. of 1 kg of the mixture = Rs. 68.20, Gain = 10%.

C.P. of 1 kg of the mixture = Rs.{100/110}x 68.20= Rs. 62   

Explanation :

 (A + B)'s 1 day's work =    1/12

 ; (B + C)'s 1 day's work =1/15

; (A + C)'s 1 day's work =    1/20

 Adding, we get: 2(A + B + C)’s 1 day’s work =1/12+1/15+1/20

=12/60=1/5

 (A + B + C)'s 1 day's work =1/10

 So, A, B and C together can complete the work in 10 days.

Explanation :

 A's 1 hour's work =1/4

 ; (B + C)'s 1 hour's work =1/3

 ; (A + C)'s 1 hour's work =1/2

 (A + B + C)'s 1 hour's work =1/4+1/3

 =7/12

 (A + B + C)'s 1 hour's work =1/4+1/3=7/12

 B's 1 hour's work =7/12-1/2 =1/12

  B alone will take 12 hours to do the work.

Explanation :

 Work done by A, B and C in 4 days ={1/10}x 4=2/5

. Remaining work =1 -2/5=3/5

 Now,3/5 work is done by B anc C in 10 days.             

 Whole work will be done by B and C in    10 x{5/3}=50/3 days.         

 (A + B + C)’s 1 day’s work =1/10

, (B + C)'s 1 day's work =    3/50

 A’s 1 day’s work =1/10-    3/50=2/50=1/25

  A alone could complete the work in 25 days.

Explanation :

 Part of the work done by A ={1/10}x 5=    1/2

 Part of the work done by B ={1/15}x 5=1/3

 Part of the work done by C = 1 -    1/2+1/3=1/6

 So, (A’s share) : (B’s share) : (C’s share) =1/2:1/3:1/6 = 3 : 2 : 1     

 A's share = Rs{.3/6}x 1500= Rs. 750, B's share = Rs.{2/6}x 1500 = Rs. 500.     

 C's share = Rs.{1/6}x 1500 = Rs. 250.         

 A’s daily wages = Rs.750/5

  = Rs. 150, B's daily wages = Rs.    500/5 = Rs. 100.     

 C’s daily wages = Rs.250/2

  = Rs. 125.         

 Daily wages of B and C = Rs. (100 + 125) = Rs. 225.