# CBSE Class 9 Mathematics and Science Exams 2018: Important questions with solutions

Feb 20, 2018 12:33 IST
CBSE Class 9 Maths & Science Important questions with solutions

In this article you will get a set of important questions for both CBSE Class 9 Mathematics and Science exams 2018.

All the questions given here are prepared after carrying a thorough analysis of the past year exam trends and the latest examination pattern. Questions have been picked from all important topics of Class 9 Maths and Science. All these questions are fully solved.

Some prominent features of the set of important questions given here are:

• Questions have been provided to cover the complete syllabus
• Follows the latest question paper format
• Separate questions have been prepared for the various sections employed in paper
• All the questions are provided with stepwise solutions which are easy to understand

CBSE Class 9 Mathematics Important Questions for Annual Exams 2018:

In class 9 Mathematics exam, there will be four sections:

 Section-A comprised of 1 mark questions (6 questions) Section-B comprised of 2 marks questions (6 questions) Section-C comprised of 3 marks questions (10 questions) Section-D comprised of 4 marks questions (8 questions)

CBSE Class 9 Mathematics Solved Practice Paper: 2018

Some sample questions from the set of important questions of class 9 Mathematics are:

Q. If the graph of equation 2x + ky = 10k, intersect x-axis at point (2, 0) then find value of k.

Sol.

Here,   2x + ky = 10k               ...(i)

At point (2, 0), equation (i) becomes:

2(2) + k(0) = 10k

⟹       4 = 10k

⟹       k = 10/4 = 0.4

Q. A batsman in his 11th innings makes a score of 68 runs and there by increases his average score by 2. What is his average score after the 11th innings?

Sol.

Let the average score of 11 innings be x.

Then the average score of 10 innings = x – 2

Total score of 11 innings = 11x

Total score of 10 innings = 10(x – 2) = 10x – 20

Score of the 11th innings = Total score of 11 innings – Total score of 10 innings

= 11x – (10x – 20)

But      x + 20x + 20 = 68        (Given )

⟹       x = 48

Hence, the average score after the 11th innings is 48.

Q. If a + b + c = 6 and ab + bc + ca = 11, find the value of a+b+c− 3abc.

Sol.

(a + b + c)2 = ab2 +c2 +2(ab bc ca
(6)= ab2 +c2 + 2 × 11
ab2 +c2 = 36 – 22 = 14
a+b+c− 3abc =( a + b + c)[ ab2 +c2 −(ab bc ca)]
= 6 × (14 − 11)

= 6 × 3 = 18

 Get the complete set of CBSE Class 9 Mathematics Important Questions 2018

CBSE Class 9 Science Important Questions for Annual Exams 2018:

In class 9 Science exam, there will be two sections consisting of 27 questions of different weightages:

 Section- A contains Two questions of 1 mark each Three questions of 2 marks each Ten questions of 3 marks each Six question of 5 marks each Section- B contains Six practical based questions of 2 marks each

CBSE Class 9 Science Solved Practice Paper: 2018

Some sample questions from the set of important questions of class 9 Science are:

Q. What is role of tissues present in multi-cellular organisms?

Ans.

The formation of tissues is important in multi-cellular organisms as :

(i) Grouping of cells and performing a single function by the group shows division of labour.

(ii) Tissues combine to form organ, organ to organ system and organ systems to organisms.

(iii) Due to improved organisation and higher efficacy organisms have high survival rate.

Q. (a) What happens to the buoyant force as more and more volume of a solid object is immersed in a liquid? When does the buoyant force become maximum?

(b)Define buoyant force. Name two factors on which buoyant force depends.

Ans.

(a) The buoyant or upthrust force increases as more and more volume of a solid object is immersed in a liquid. When object is fully immersed in water the buoyant force becomes maximum.

(b)Fluid applies an upward force on a solid which is partially or fully submerged in liquid. This phenomenon is called buoyancy (Upthrust) and applied upward force is called buoyant force.

Two factors on which buoyant force depends:

• Volume or shape of object.

• Density of fluid in which object is immersed.

Q. In which of the two, glycerine or kerosene, the loss in weight of a solid when fully immersed in them will be more and why ?

Ans.

Density of glycerine is more than that of kerosene.

A liquid having higher density exerts more upthrust force on object than other liquid having low density. Thus, greater the density of a liquid, the more will be the the buoyant force exerted on the object immersed in it.  Now, due to this greater upthrust (buyont force), the object experiences greater apparent weight loss.

Thus in case of glycerine, the loss in weight of a solid when fully immersed in it will be more than when immersed in kerosene.

 Get the complete set of CBSE Class 9 Science Important Questions 2018

Practicing all the important questions given here will help students make a quick but effective preparation for their CBSE Class 9 Exams 2018.

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