Tips and Ticks Time and Work Problems - Shortcut Tricks and Formulas


Tips and Ticks 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

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Average calculation

N = the number of terms  .

S = the sum of the numbers in the set.

Average = S/N .


For example.

The marks of a student in five subjects are 96, 94, 92, 87, and 81, then what is the average score of the student?.

N = 5.

S = 96 + 94 + 92 + 87 + 81 = 450.

A = 450/5 = 90.


Another type questions .

1). There are 36 boys and 44 girls in a class. The average score of boys is 40 and girls are 35. Then what will be the average mark? .


Total mark of 36 boys = 36 x 40 = 1440.

Total mark of 44 girls = 35 x 44 = 1540.

Total mark of 80 Students = 1440 + 1540 = 2980 .

Average mark of the class = (2980 / 80).

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BODMAS Rule

BODMAS is an acronym and it stands for Bracket, Of, Division, Multiplication, Addition and Subtraction. .

This explains the order of operations to solve an expression. According to Bodmas rule, if an expression contains brackets ((), {}, []) we have to first solve/simplify the bracket followed by of (powers and roots etc.), then division , multiplication , addition and subtraction from left to right. .

Example :.

7 + (6 × 52 + 3) =   7 + (6 × 25 + 3).

7 + (150 + 3).

7 + (153).

7 + 153 .

Ans: 160. .

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Divisibility Rule

What is the divisibility by 2 Rule?.
Even numbers are multiples of 2. A number is even if ends in 0,2,4,6, or 8.
What is the divisibility by 3 rule?.
A number is divisible by 3 if the sum of its digits is divisible by 3.
372, for instance, is divisible by 3 since sum of its digits (3+7+2) is 12. And 12 is divisible by 3.
What is the divisibility by 4 rule?.
A number is divisible by 4 if the number\'s  last two digits are divisible by 4.
9,312, for instance, is divisible by 4 since its last 2 digits are 12. And 12 is divisible by 4.
What is the divisibility by 5 rule?.
A number is divisible by 5 if its last digit is a 0 or 5.
What is the divisibility by 6 rule?.
Since 6 is a multiple of 2 and 3, the rules for divisibility by 6 are a combination of the rule for 2 and the rule for   3.
Divisibility by 8 Rule.
A number passes the test for 8 if the las...

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