# Important 3 Marks Questions for CBSE 8 Maths

Class 8th CBSE is a very important stage in the development of the fundamentals of a student. As the basics of Maths and Science help students to understand complex topics which will come in 9th standard. Most of the subjects in class 8 are vast, where some of them require not only memorization but also requires skill. One such is the subject of Mathematics, which seems to be a nightmare for students and requires a lot of practice to boost confidence. So we at BYJU’S provide students of Class 8 with important 3 marks question as per the 2019 exam, which can be beneficial for them in their examination.

Students preparing for CBSE Class 8 Maths Examination are advised to practice the given question for Mathematics:

Q1) Construct a frequency distribution table for the data on weighs (in kgs) of 20 students of a class using class intervals 30-35, 35-40 and so on.

40, 33, 56, 31, 34, 49, 55, 57, 44, 38, 38, 48, 53, 46, 36, 41, 49 ,42, 47, 39

Q2) The number of employees in a office, speaking different languages is given below. Display the data in a pie chart.

 Language Hindi English Marathi Tamil Bengali Total Number of students 30 12 9 7 4 62

Q3) Classify the following polynomials as monomials, binomials and trinomials:

1. a) $5xyz^{2}$ – 3zy
2. b) $\frac{a}{2}+\frac{b}{2}-ab$
3. c) pqr

Q4) Draw the line passing through (2,3) and (3,2). Find the coordinates of the points at which this line meets the x-axis and y-axis.

Q5) Simplify:

$\left \{ \left ( \frac{1}{3} \right )^{-2}-\left (\frac{1}{2} \right )^{-3} \right \}\div \left (\frac{1}{4} \right )^{-2}$

Q6) Subtract 3a(a + b – c) – 2b( a – b + c) from 4c (-a + b + c) .

Q7) An electric pole 15m high, casts a shadow of 10m. Find the height of the tree that casts a shadow of 15m under similar conditions.

Q8) A cuboid is dimension 60 cm x 54 cm x 30 cm. How many small cubes with side 6 cm can be placed in the given cuboid?

Q9 ) If 18 workers can build a sloping roof of a building in 48 hours, how many workers will be required to do the same work in 30 hours ?

Q10) Find the compound interest on Rs. 5000 for 2 years at the rate of 10% per annum compounded annually.

Q11) Subtract $5x^{2}-4y^{2}$ + 16y – 3 from $7x^{2}-4xy+8y^{2}+5x-3y$

Q12) The diagonal of quadrilateral shaped field is 24 m and the perpendicular dropped on it from the remaining opposite vertices are 8 m and 13 m. Find the area of the field.

Q13) A machine in a soft drink factory fills 840 pepsi bottles in hours. How many bottles will it fill in 6 hours.

Q14) Divide:

$(7x^{2}+14x)$ by (x + 2)

Q15) A storage place is in the form of a cuboid of measures 60 m x 40 m x 30 m . How many cuboidal boxes can be stored in it, if the volume of one box is $0.8m^{3}$ .

Q16) Show that:

$(3x+7)^{2}-84x = (3x-7)^{2}$

Q17) If any object has 20 faces, 12 vertices then find the value of Edges by using Euler’s formula.

Q18) Four fifth of a number is more than three fourth of the number by 4. Find the number.

Q19) Find five rational numbers between $\frac{-1}{3}$ and $\frac{1}{3}$<

Q20) The diagonal of quadrilateral shaped field is 24m and the perpendiculars dropped on it from the remaining opposite vertices are 10m and 15m. Find the area of the field.

### Last Year  3 marks Questions for Class 8 Maths

1. A shopkeeper purchased 300 bulbs for Rs.12 each. However, 5 bulbs were fused and had to be thrown away. The remaining bulb was sold in Rs.15 each. Find his gain and loss per cent.
2. A shopkeeper buys 90 articles for Rs.2700 and sells them at a profit of 18%. Find the selling price of one article.
3. Using the laws of exponents, evaluate the following:
1. (2)-3 x (1/6)-3 x (10 + 20 + 30)-2
4. The cost of the sewing machine is Rs. 7000. Its value depreciates at 8% per annum. Find the value of the machine after 2 years.
5. Suppose 5kg of sugar contains 5 x 107 crystals. How many sugar crystals are there in:
1. 2 kg of sugar?
2. 1.2 kg of sugar?
6. The diagonal of a quadrilateral shaped field is 24m and perpendicular dropped on it from the remaining opposite vertices are 10m and 15m. Find the area of the field.
7. Find the area of a rhombus whose is 6cm and altitude is 4cm. If one of its diagonal is 8cm long, then find the length of another diagonal.
8. Show that: (9p – 5q)2 + 180 pq = (9p+5q)2
9. Show that: (2.5p – 1.5q)2 – (2.5p+1.5q)2
10. Factorise: p4-81