# Time and Work Problems - Shortcut Tricks and Formulas

## Time and Work Problems - Shortcut Tricks and Formulas

Problems Type 1:

A can finish work in X days.

B can finish work in Y days.

Both can finish in Z days = (X*Y) / (X+Y).

Problems Type 2:

Both A and B together can do work in T days.

A can do this work in X days.

then, B can do it in Y days = (X*T) / (X-T)

Problems Type 3:

A can finish work in X days.

B can finish work in Y days.

C can finish work in Z days.

Together they can do work in T days = (X*Y*Z)/ [(X*Y)+(Y*Z)+(X*Z)]

Problems Type 4:

A can finish work in X days.

B can finish work in Y days.

A*X = B*Y

Y = (A*X) / B

Problems Type 5:

A can finish work in X days.

B can finish work in Y days.

A left work after P days then B need to work Q days

Q = [(X - P) / X ] * Y

Problems Type 6:

M1 person can do W1 work in D1 days and H1 hours

M2 person can do W2 work in D2 days and H2 hours

M1D1H1 = M2D2H2

Problems on Train with Explanation and Shortcuts

Formula :  .

Train Speed = Distance / Time.

Points to Remember .

To change km/hr into m/sec, we need to multiply it by 5 / 18. .

Example:.

90 km/hr means.

90 x 5 / 18.

= (5 x 5 ).

= 25 m/sec.

And if we need to convert m/sec into km/hr, we multiply it by 18 / 5.

Example:.

90 m/sec means.

90 x 18 / 5.

= ( 18 x 18 ).

= 324 km/hr.

Time taken by a train of length l meters to pass a pole or standing man or a signal post is equal to the time taken by the train to cover l meters.
Time taken by a train of length l meters to pass a stationary object of length b meters is the time taken by the train to cover (l + b) meters.
Suppose two trains or two objects bodies are mo...

Tricks and Tips for Boat and Stream type Questions

Shortcut tricks on boats and streams are one of the most important topics in exams. These are the formulas and examples on Boats and Streams (Cyclist and the wind or Swimmer and stream) questions. These examples will help you to better understand shortcut tricks on boats and streams questions.

There are multiple types of questions asked from these topics. The speed of the boat in still water and the speed of stream will give in questions, You have to find the time taken by boat to go upstream and downstream. .
The speed of the boat in up and down stream will give in question,  you need to find the average speed of the boat.
The speed of boat to go up or down the stream will give in question, you need to find speed of boat in still water and speed of stream.
The time taken by boat to reach a place in up and downstream will given in question, you need to find the distance to the place.

LINE_F...

Handshake Problem

Suppose there are n people in the party. The first person shakes hand with the other (n-1) guests. The second guest shakes hand with the other (n-2) guests. this will continue until the (n-1) th guest shakes hand with the nth guest.

Total number of handshakes is (n-1) + (n-2).. + 3 + 2 + 1. .

= ((n-1)(n))/2 .

For example, 6 people in a party shake hand with other guests. So how many handshakes will be there?.

=((6-1)(6))/2.

=15.

...