Number of page copied by (Subhash+ Prakash) in 1 hour = ³⁰⁰/₄₀ = 7.5 pages;

Subhash copied pages in one hour = ⁵⁰/₁₀ = 5 pages

Hence, Prakash copied pages in one hour = 7.5-5 = 2.5;

Thus,

Prakash can copied 30 pages in = ³⁰/_2.5 = 12 hour.

A and B can complete the work in 18 days, work rate = ¹⁰⁰/₁₈ = 5.55% per day.

They together can complete the work in 12 days = 5.55 * 12 = 66.66%.

Now, A leaves and B takes another 15 days to complete the whole work, Work rate of B = ^33.33/₁₅ = 2.22% per day.

B work for (12+15) = 27 days.

So, Work done by B in 27 days = 2.22*27 = 60% And So 40% work is done by A. so there share should be 60% and 40% ratio.

A's share = 40% of 1500 = Rs. 600.

\begin{align} & \left( {{\text{A + B + C}}} \right){\text{'s}}\, {\text{1}}\, {\text{day's}}\, {\text{work}} = \frac{1}{6} \cr & \left( {{\text{A + B}}} \right){\text{'s}}\, {\text{1}}\, {\text{day's}}\, {\text{work}} = \frac{1}{8} \cr & \left( {{\text{B + C}}} \right){\text{'s}}\, {\text{1}}\, {\text{day's}}\, {\text{work}} = \frac{1}{{12}} \cr & \therefore \left( {{\text{A + C}}} \right){\text{'s}}\, {\text{1}}\, {\text{day's}}\, {\text{work}} \cr & = \left( {2 \times \frac{1}{6}} \right) - \left( {\frac{1}{8} + \frac{1}{{12}}} \right) \cr & = \left( {\frac{1}{3} - \frac{5}{{24}}} \right) \cr & = \frac{3}{{24}} \cr & = \frac{1}{8} \cr & {\text{So, }}\, {\text{A}}\, {\text{and}}\, {\text{C}}\, {\text{together}}\, {\text{will}}\, {\text{do}}\, \cr & {\text{the}}\, {\text{work}}\, {\text{in}}\, {\text{8}}\, {\text{days}} \cr\end{align}

A can complete the work in 7*6 = 42 hours;

1 hour's work of A = ¹/₄₂;

B can complete the work in 7*8 = 56 hours;

1 hour's work of B = ¹/₅₆;

(A+B)'s 1 hour's work = ¹/₄₂ + ¹/₅₆ = ⁹⁸/₄₂ * 56;

(A+B) will take time to complete whole work,

working 7 hours a day = 42 * ⁵⁶/₉₈ = 24 hours;

Let X be the no. of days taken, working 8 hours a day to complete the work by A and B together.

Now, using work equivalence method ;

24 = 8 * X;

X = ²⁴/₈ = 3 days.

\begin{align} & {\text{Number}}\, {\text{of}}\, {\text{pages}}\, {\text{typed}}\, {\text{by}}\, {\text{Ravi}}\, {\text{in}}\, {\text{1}}\, {\text{hour}} \cr & = \frac{{32}}{6} = \frac{{16}}{3} \cr & {\text{Number}}\, {\text{of}}\, {\text{pages}}\, {\text{typed}}\, {\text{by}}\, {\text{Kumar}}\, {\text{in}}\, {\text{1}}\, {\text{hour}} \cr & = \frac{{40}}{5} = 8 \cr & {\text{Number}}\, {\text{of}}\, {\text{pages}}\, {\text{typed}}\, {\text{by}}\, {\text{both}}\, {\text{in}}\, {\text{1}}\, {\text{hour}} \cr & = \left( {\frac{{16}}{3} + 8} \right) = \frac{{40}}{3} \cr & \therefore {\text{Time}}\, {\text{taken}}\, {\text{by}}\, {\text{both}}\, {\text{to}}\, {\text{type}}\, {\text{110}}\, {\text{pages}} \cr & = \left( {110 \times \frac{3}{{40}}} \right){\text{hours}} \cr & = 8\frac{1}{4}\, {\text{hours}}\, {\text{(or)}}\, {\text{8}}\, {\text{hours}}\, {\text{15}}\, {\text{minutes}} \cr\end{align}