The topic Indices and Surds is a part of the Number System vertical of the Quantitative Aptitude section in the MBA entrance exam. Although we can observe from the trend that the frequency of occurrence of Indices and Surds questions in this topic has decreased, we cannot ignore this topic entirely as we can always expect 1-2 Indices and Surds questions on this topic in many MBA entrance exams.
Many exams ask questions on Indices and Surds. These may range from 1-2 Indices and Surds questions which are usually assigned easy to moderate level of difficulty. Hence, it is wise to cover this topic to score well.
Exam | Year | No of Questions | Level of Difficulty |
2018 | 1 | Moderate | |
2018 | 1 | Easy | |
2019 | 1 | Moderate | |
2018 | 1 | Easy | |
SNAP | 2018 | 1 | Easy |
Numbers that can be written as √a + √b, where a and b are not perfect squares and natural numbers. Hence, the numbers in the form of √5, 5√7, ……. x√y
Name of the Rule | Conversion |
Division | a^{m}/ a^{n} = a^{m-n} |
a^{n} / b^{n} = (a / b)^{n} | |
Multiplication | a^{n}⋅ a^{m} = a^{m+n} |
a^{n} ⋅ b^{n} = (a ⋅ b)^{n} | |
Power | (a^{n})^{m} = a^{n}^{⋅}^{m} |
_{a}n^{m} = _{a}^{(nm)} | |
^{m}√(a^{n}) = a ^{n/m} | |
^{n}√a = a^{1/n} | |
a^{-n} = 1 / a^{n} |
1) in surds problems Surd nx can be simplified if the factor of x is a perfect square
2)Any number raised to the power zero always equals one. (Eg: x 0 = 1)
3) The conjugate of (x√a + y√b) is (x√a – y√b)
4) If the denominator in a fraction has a surd, then rationalize the denominator by multiplying both numerator and denominator by a conjugate surd
5) Different expressions can be simplified by rationalizing the denominator and eliminating the surd
6) Every surd is an irrational number in surd questions.
If m and n are integers such that (√2)^19 * 3^4 * 4^2 * 9^m * 8^n = 3^n * 16^m (4√64) then m is?
1. -20
2. -24
3. -16
4. -12
Answer – 12
Explanation:
Given, √2^19 3^4 4^2 9^m 8^n=3^n 16^m ∜64
Or 2^(19/2)×3^4×2^4×3^2m×2^3n= 3^n×2^4m×2^(6/4)
2^(19/2+4+3n)×3^(4+2m)=3^n×2^((4m+6/4) )
Comparing both sides,
n = 4+2m
19/2 +4 + 3n = 4m + 6/4
Or (19 + 8)/2 + 3(4+2m) = 4m + 3/2
27/2 + 12 + 6m = 4m + 3/2
6m -4m = 3/2 – 27/2 -12
2m = -24
Thus m = -12
If 17x = 4913, find the value of 22x-1.
a) 16
b) 32
c) 64
d) 128
17x = 4913
⇒17x = 4913
⇒17x = (17)3
⇒x = 3
Value of 22x-1 ⇒ 22.3-1⇒ 25 = 32
If 2x × 8(1/4) = 2(1/4) then find the value of x
As bases are not equal we cannot add the indices, hence first convert all the numbers with the same base.
2x × (23)(1/8) = 2(1/4)
Hint:
Law of Indices (xm)n = xmn
2x × 2(3/4) = 2(1/4)
2[x + (3/4)] = 2(1/4)
If 4 (x – y) = 64 and 4 (x + y) = 1024, then find the value of x.
a. 3
b. 1
c. 6
d. 4
4 (x – y) = 64
4 (x – y) = 64 = 43
Equation 1) x – y = 3
4 (x + y) = 1024 = 45
Equation 2) x + y = 5
Solving equation (1) and (2), we get
x = 4 and y = 1
Crosscheck the answers by substituting the values of x and y in the given expression.
4 (4 – 1) = 43 = 64 and 4 (4 + 1) = 45 = 1024
Hence, the answers x = 4 and y = 1 are correct.
If a and b are whole numbers such that ab = 121, then find the value of (a – 1)b + 1
a. 0
b. 10
c. 102
d. 103
121 = 112 , hence value of a = 11 and b = 2 can be considered.
Therefore, the value of (a – 1)b + 1 = (11 – 1) 2 + 1= 103
Preparing for Indices and Surds will require a basic understanding of the key concepts and speedy calculation along with hard work and dedication. Here are some Level-wise preparatory guidelines to follow:
1. Move on to more complex surds and indices questions, attempt beginner and intermediate level mock on concepts of Indices and Surds.
2. Solve previous year CAT questions on Indices and Surds and time yourself. Do not get stuck on one question and try to solve easy questions first from surds and indices questions pdf.
3. Keep attempting mocks to check your performance.
4. Practice MBAP Topic wise Previous Year CAT paper, this can be utilized to enhance your performance.
1. For advanced level preparation, start practicing Indices and Surds questions from MBAP CAT Advance E books – How to Prepare for Quantitative Aptitude for the CAT, authored by Arun Sharma.
2. Indices and Surds questions in Arun Sharma are categorized into Level of Difficulty (LOD), based upon your preparation level, start attempting 3 or 4 questions daily.
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