Question : A and B can complete a piece of work in 13 and 17 days respectively. A begins to do the work, and they work alternatively one at a time for one day each. The whole work will be completed in:

Option 1: $17 \frac{11}{17}$ days

Option 2: $17 \frac{17}{19}$ days

Option 3: $14 \frac{11}{17}$ days

Option 4: $11 \frac{11}{17}$ days

Question : P, Q, and R can complete a piece of work in 10 days, 15 days, and 20 days, respectively. If they work together, in how many days can they finish the same work?

Option 1: $4 \frac{8}{13}$

Option 2: $4 \frac{3}{7}$

Option 3: $4 \frac{7}{13}$

Option 4: $4 \frac{5}{7}$

Question : A and B can do a piece of work in 18 days, B and C in 24 days and A and C in 36 days. Working together, they can do the work in:

Option 1: 12 days

Option 2: 13 days

Option 3: 16 days

Option 4: 26 days

Question : To do a certain work, the ratio of the efficiencies of A and B is 7 : 5. Working together, they can complete the same work in $17 \frac{1}{2}$ days. A alone will complete 60% of the same work in:

Option 1: 18 days

Option 2: 15 days

Option 3: 16 days

Option 4: 21 days

Question : P and Q together complete a job in $4 \frac{2}{5}$ days. R and S complete the same job in $4 \frac{8}{9}$ days. If P, Q, R, and S work together, how many days do they need to complete the same job?

Option 1: $2 \frac{7}{18}$

Option 2: $1 \frac{7}{18}$

Option 3: $1 \frac{6}{19}$

Option 4: $2 \frac{6}{19}$