Time and Work Questions – Concept, Formula & Tricks
Time and Work Formula
- Work from Days:If A can do a piece of work in n days, then A’s 1 day’s work =1.n
- Days from Work:If A’s 1 day’s work =1,then A can finish the work in n days.n
- Ratio:If A is thrice as good a workman as B, then:Ratio of work done by A and B = 3 : 1.Ratio of times taken by A and B to finish a work = 1 : 3.
Time And Work Tricks
Time= Work done/Efficiency
- When work is same.
- If A can do a piece of work in n days.
Then, per day working efficiency of A = 1/n
- If working efficiency of A & B is → x : y.
Then, the time taken by A & B to finish the work is in the ratio → y : xe.g. If A does three times faster work than ‘B’, then the ratio of work done by A and B is 3: 1.
Then, Ratio of time taken by A & B = 1 : 3
- If A can do a piece of work is x days and B can do a piece of work in y days, then both of them working together will do the same work in
- If A, B & C will working alone, can complete a work in x, y and z days, respectively, then they will together complete the work in
- Two persons A & B, working together, can complete a piece of work in x days. If A, working alone, can complete the work in y days, then B, working alone, will complete the work in
- If A & B working together, can finish a piece of work is x days, B & C in y days, C & A in z days. Then, A + B + C working together will finish the job is
- If A can finish a work in x days and B is k times efficient than A, then the time taken by both A and B, working together to complete the work is
- If A & B working together can finish a work in x days & B is k times efficient than A, then the time taken by,
A working Alone will take ⇒ (k + 1) x
B working Alone will take ⇒ ((k+1)/k)x
- If A working Alone takes a days more than A & B, & B working Alone takes b days more than A & B. Then ,
Number of days, taken by A & B working together to finish a job is = √ab