Tricks to solve quantitative aptitude problems

Will you please give me some short tricks and formulas to solve quantitative aptitude problems??

Solving the aptitude test questions with accuracy as well as quickly is asked in most of the competitive, entrance and qualifying examinations.

Here I am giving you some Short tricks to solve quantitative aptitude problems

Formulas of Number Series
1 + 2 + 3 + 4 + 5 + … + n = n(n + 1)/2
(13 + 23 + 33 + ..... + n3) = (n(n + 1)/ 2)2
(12 + 22 + 32 + ..... + n2) = n ( n + 1 ) (2n + 1) / 6
Sum of first n odd numbers = n2
Sum of first n even numbers = n (n + 1)

Mathematical Formulas
(a + b)(a - b) = (a2 - b2)
(a + b)2 = (a2 + b2 + 2ab)
(a3 - b3) = (a - b)(a2 + ab + b2)
(a3 + b3 + c3 - 3abc) = (a + b + c)(a2 + b2 + c2 - ab - bc - ac)
When a + b + c = 0, then a3 + b3 + c3 = 3abc
(a + b)n = an + (nC1)an-1b + (nC2)an-2b2 + … + (nCn-1)abn-1 + bn
(a - b)2 = (a2 + b2 - 2ab)
(a + b + c)2 = a2 + b2 + c2 + 2(ab + bc + ca)
(a3 + b3) = (a + b)(a2 - ab + b2)

Shortcuts for number divisibility check
-A number is divisible by 2, if its unit's digit is any of 0, 2, 4, 6, 8.
-A number is divisible by 3, if the sum of its digits is divisible by 3.
-A number is divisible by 4, if the number formed by the last two digits is divisible by 4.
-A number is divisible by 5, if its unit's digit is either 0 or 5.
-A number is divisible by 6, if it is divisible by both 2 and 3.
-A number is divisible by 12, if it is divisible by both 4 and 3.
-A number is divisible by 14, if it is divisible by 2 as well as 7.
-Two numbers are said to be co-primes if their H.C.F. is 1. To find if a number, say y is divisible by x, find m and n such that m * n = x and m and n are co-prime numbers. If y is divisible by both m and n then it is divisible by x.
-A number is divisible by 8, if the number formed by the last three digits of the given number is divisible by 8.
-A number is divisible by 9, if the sum of its digits is divisible by 9.
-A number is divisible by 10, if it ends with 0.
-A number is divisible by 11, if the difference of the sum of its digits at odd places and the sum of its digits at even places, is either 0 or a number divisible by 11.

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Answered By StudyChaCha Member