Shortcut of Combination and Probability
Shortcut 99: nCr=n!/[r!(n-r)!] Question: In how many ways 2 shirts and 3 pants can be selected from 5 shirts and 7 pants? Answer: Selecting...
Shortcuts
-
-
Shortcut of Permutation-2
Shortcut 95: Repeated elements n!/(a!*b!) Question: In how many ways the letters of the word “ENVIRONMENT” can be arranged? Answer: n = 11 Let,...
-
Shortcut of Permutation-1
Shortcut 91: Events Dependent=multiplication Independent =addition Question: There 3 busses from city A to city B and there are 5 busses from city...
-
Shortcut of Calendar and Clocks
Shortcut 87: Using the odd days Question: Find the day of birth of MS Dhoni (7 July, 1981), if 31 Dec 1999 is Friday...
-
Shortcut of Heights and Distances
Shortcut 85: Using tanƟ Ɵ tan 0 0 30 45 1 60 90 Question:...
-
Shortcut of LCM and HCF
Shortcut 82: Maximum number of items per group Take HCF Question: There are 40, 45 and 50 balls in three different colors. They have...
-
Shortcut of Number system
Shortcut 77: Divisibility test Divisibleby Rule 2 Last digit of a number should be 0,2,4,6, or 8 3 Sum of the digit should be divisible...
-
Shortcut of Simple and Compound Interest
Shortcut 75: Simple interest P = Principle amount invested or borrowed R = Rate of interest per term N = Number of terms Term =...
-
Shortcut of Pipes and Cisterns
Shortcut 73: One pipe fills and another empties Question: Pipe A can fill a tank in 4 hours and pipe B can empty the tank...
-
Shortcut of Time and work-3
Shortcut 68: Three men working together Question: A can do a work in 40 days, B in 50 days and C in 60 days. If...
