Practice Math Class 7th to 9th


Mathematics Practice Set


1. Probability (āϏāĻŽā§āĻ­āĻžā§ąāύāĻž)


Q1. A box contains 4 red pencils, 6 blue pencils and 5 green pencils. What is the probability of picking a green pencil at random ? (āĻĒā§ā§°āĻļā§āύ ā§§āĨ¤ āĻāϟāĻž āĻŦāĻžāĻ•āϚāϤ ā§ĒāϟāĻž ā§°āĻ™āĻž, ā§ŦāϟāĻž āύ⧀āϞāĻž āφ⧰⧁ ā§ĢāϟāĻž āϏ⧇āωāĻœā§€āϝāĻŧāĻž āĻĒ⧇āĻžā§āϚāĻŋāϞ āφāϛ⧇āĨ¤ āϝāĻžāĻĻ⧃āĻšā§āĻ›āĻŋāĻ•āĻ­āĻžā§ąā§‡ āĻāϟāĻž āϏ⧇āωāĻœā§€āϝāĻŧāĻž āĻĒ⧇āĻžā§āϚāĻŋāϞ āωāĻ āĻžā§° āϏāĻŽā§āĻ­āĻžā§ąāύāĻž āĻ•āĻŋāĻŽāĻžāύ ?)


Solution (āϏāĻŽāĻžāϧāĻžāύ):


Total pencils (āĻŽā§āĻ  āĻĒ⧇āĻžā§āϚāĻŋāϞ)
= 4 + 6 + 5
= 15


Green pencils (āϏ⧇āωāĻœā§€āϝāĻŧāĻž āĻĒ⧇āĻžā§āϚāĻŋāϞ)
= 5


Probability (āϏāĻŽā§āĻ­āĻžā§ąāύāĻž)


Probability = Favourable Outcomes / Total Outcomes = 5/ 15 = 1/3 


Ans (āωāĻ¤ā§āϤ⧰): Probability = 1/3 (āϏāĻŽā§āĻ­āĻžā§ąāύāĻž = ā§§/ā§Š)



2. Algebraic Expression (āĻŦā§€āϜāĻ—āĻžāĻŖāĻŋāϤāĻŋāĻ• ā§°āĻžāĻļāĻŋ)


Q2. Simplify: āϏ⧰āϞ āϕ⧰āĻ•āσ 4(3x − 2) − 2(2x + 5)


Solution (āϏāĻŽāĻžāϧāĻžāύ):


4(3x−2) − 2(2x+5) 


Open the brackets (āĻŦā§ā§°ā§‡āϕ⧇āϟ āĻ–ā§‹āϞāĻ•) =12x − 8 − 4x − 10


Combine like terms (āĻāϕ⧇ āϧ⧰āĻŖā§° āĻĒāĻĻ āĻāϕ⧇āϞāĻ— āϕ⧰āĻ•) = (12x − 4x) − (8 + 10) 


Ans (āωāĻ¤ā§āϤ⧰): 8x − 18


3. Linear Equation(āϏ⧰āϞ āϏāĻŽā§€āϕ⧰āĻŖ)


Q3. Solve for x : (x ā§° āĻŽāĻžāύ āωāϞāĻŋāϝāĻŧāĻžāĻ“āĻ•āσ): 3x − 9 = 18


Solution (āϏāĻŽāĻžāϧāĻžāύ):


3x − 9 = 18


Add 9 to both sides (āĻĻ⧁āϝāĻŧā§‹āĻĢāĻžāϞ⧇ ⧝ āϝ⧋āĻ— āϕ⧰āĻ•) = 3x = 18 + 9 = 27


Divide by 3 (ā§Š āĻĻā§āĻŦāĻžā§°āĻž āĻ­āĻžāĻ— āϕ⧰āĻ•) : x = 27/3 = 9 


Ans (āωāĻ¤ā§āϤ⧰): x = 9


4. Perimeter of Rectangle (āφāϝāĻŧāϤāĻ•ā§āώ⧇āĻ¤ā§ā§°ā§° āĻĒā§°āĻŋāϏ⧀āĻŽāĻž)


Q4.  A rectangular table is 12 cm long and 7 cm wide. Find its perimeterāĻĒā§ā§°āĻļā§āύ ā§ĒāĨ¤ āĻāϟāĻž āφāϝāĻŧāϤāĻ•ā§āώ⧇āĻ¤ā§ā§°ā§° āĻĻā§ˆā§°ā§āĻ˜ā§āϝ 12 cm āφ⧰⧁ āĻĒā§ā§°āĻ¸ā§āĻĨ 7 cmāĨ¤ āχāϝāĻŧāĻžā§° āĻĒā§°āĻŋāϏ⧀āĻŽāĻž āύāĻŋā§°ā§āĻŖāϝāĻŧ āϕ⧰āĻ•āĨ¤


Solution (āϏāĻŽāĻžāϧāĻžāύ):


Formula (āϏ⧂āĻ¤ā§ā§°) : Perimete r= 2(Length+Width) = 2(12+7) = 2×19 =


Ans (āωāĻ¤ā§āϤ⧰): Perimeter = 38 cm (āĻĒā§°āĻŋāϏ⧀āĻŽāĻž = ā§Šā§Ž āĻšā§‡āĻŽāĻŋ)


5. Discount(⧰⧇āĻšāĻžāχ)


Q5.  A jacket is marked at $120. During a sale, it is reduced by 25%. Find the discount and the sale price. āĻĒā§ā§°āĻļā§āύ ā§ĢāĨ¤ āĻāϟāĻž āĻœā§‡āϕ⧇āϟ⧰ āĻŽā§‚āĻ˛ā§āϝ $120āĨ¤ āĻŦāĻŋāĻ•ā§ā§°ā§€ā§° āϏāĻŽāϝāĻŧāϤ āχāϝāĻŧāĻžāϤ 25% ⧰⧇āĻšāĻžāχ āĻĻāĻŋāϝāĻŧāĻž āĻšā§ˆāϛ⧇āĨ¤ ⧰⧇āĻšāĻžāχ⧰ āĻĒā§°āĻŋāĻŽāĻžāĻŖ āφ⧰⧁ āĻŦāĻŋāĻ•ā§ā§°āϝāĻŧ āĻŽā§‚āĻ˛ā§āϝ āύāĻŋā§°ā§āĻŖāϝāĻŧ āϕ⧰āĻ•āĨ¤


Solution (āϏāĻŽāĻžāϧāĻžāύ):


Marked Price (āĻŽā§‚āϞ āĻŽā§‚āĻ˛ā§āϝ) = $120


Discount (⧰⧇āĻšāĻžāχ) = 25/100 × 120 =


Sale Price (āĻŦāĻŋāĻ•ā§ā§°āϝāĻŧ āĻŽā§‚āĻ˛ā§āϝ) = 120 − 30 =


Ans (āωāĻ¤ā§āϤ⧰): Discount (⧰⧇āĻšāĻžāχ) = $30,  Sale Price (āĻŦāĻŋāĻ•ā§ā§°āϝāĻŧ āĻŽā§‚āĻ˛ā§āϝ) = $90