Important Quiz of Algebra for SSC

#everydayquiz #algebra #ssc

Algebra is the easiest topic for SSC because you don't have to memorize any formula for it and all the

questions can be solved within 10 seconds with jugaad.

First let me share with you the concept of symmetrical expressions (as I call it). A symmetrical

expression is the one in which the weight of all the variables (a, b, c, etc.) is equal. Examples will make

things clear.

Hack - 1 : "Whenever you encounter a symmetrical equation in any question, you can safely assume

a = b = c (even if it is not given in the question)"

Let's solve previous year questions

Here you can see that the LHS as well as the RHS of the equation is symmetrical, hence a = b = c

Answer : (A)

We put a = b = c, hence (a+c)/b becomes (a+a)/a,2a/a or 2

Answer : (B)

In this question we have to find the value of x.

Here the equation is completely symmetrical, hence we assume a = b = c

Put b=a, c=a (so that the whole equation is in terms of 'a')

Now LHS becomes 3(x – a^2)/2a

RHS = 12a

Solving this, you will get, x = 9a^2

From here we get that the value of x is 9a^2

Now put a = b = c in all the 4 options and check which option gives you the value 9a 2

A) 9a^2

B) 3a^2

C) 3a^2

D) 0

Answer : (A)

Sometimes equations are complex and you will find it difficult to assume values for the variables.

2bc/3bc+2ca/3ca+2ab/3ab

2/3+2/3+⅔

6/3 =2

Please note that this hack is also applicable only for symmetrical equations.

Now let us see some other questions where you can assume the values.

if here we assume value of x=1 then 1+1/1=2 and avg 2/2=1 so when x=1 a=1 now,, avg of asked x^3+1/x^3 also be 1,,,now jst put value of a=1 and answer will be D

Here on putting a=1, you will find that both the options A and B will give the same result. Hence put a =

4, then x = 1.25

The value of the expression = 3/2

Answer : (A)

Here, I have straight away put a=4, instead of 2 or 3 because in the question we have to calculate the

square root of a. So if you will take a perfect square(like 4), the calculations will be much easier.

Note : In this question we calculated the square of 1.25, which is 1.5625. For those who don't know the

trick for calculating the square of numbers ending with '5' (like 15, 65, 135, 225, etc.), let me share it.

thinking process is like,,,there is minus sign in the question so those who have no minus will never be answer ,,we can eliminate c,, and A will be eliminte bcz two minus sign will make one plus sign,, now we have option B and D,,, now you can go for solving,,,

Put a = 0

Hence, (a^2 + 2a)^2 + 12(a^2 + 2a) – 45 = -45

Now put a = 0 in all the four options and check which one is giving -45 as output

(a) 45

(b) -45

(d) -45

Hence (b) and (d), two options are possible

Now put a = 1

(a^2 + 2a)^2 + 12(a^2 + 2a) – 45 = 0

Put a = 1 in options (b) and (d) to see which one will give zero as the output

Answer: (b)

Approximation in Algebra