Question A child’s game has 8 triangles of which 3 are blue and rest are red, and 10 squares of which 6 are blue and rest are red. One piece is lost at random. Question 1 How many triangles are of red colour and how many squares are of red colour? (a) 5, 4 (b) 4, 5 (c) 5, 5 (d) 8, 6 Given that
Game has 8 triangles of which 3 are blue & rest are red,
And 10 squares of which 6 are blue & rest are red
Thus, there are
8 triangles – 3 blue and 5 red
10 squares – 6 blue, 4 red
So, the correct answer is (A)
Question 2 Find the probability that lost piece is triangle. (A) 4/9 (B) 5/9 (C) 1/3 (D) 5/18Total Triangles = 8
Total squares = 10
Thus,
Total pieces = 10 + 8 = 18
Now,
Probability that lost piece is triangle = (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑡𝑟𝑖𝑎𝑛𝑔𝑙𝑒𝑠)/(𝑇𝑜𝑡𝑎𝑙 𝑝𝑖𝑒𝑐𝑒𝑠)
= 8/18
= 𝟒/𝟗
So, the correct answer is (A)
Question 3 Find the probability that lost piece is square. (A) 4/9 (B) 5/9 (C) 1/3 (D) 5/18Total Triangles = 8
Total Squares = 10
Thus,
Total pieces = 10 + 8 = 18
Now,
Probability that lost piece is square = (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑠𝑞𝑢𝑎𝑟𝑒𝑠)/(𝑇𝑜𝑡𝑎𝑙 𝑝𝑖𝑒𝑐𝑒𝑠)
= 10/18
= 𝟓/𝟗
So, the correct answer is (B)
Question 4 Find the probability that lost piece is square of blue colour. (A) 4/9 (B) 5/9 (C) 1/3 (D) 5/18Now, we have
8 triangles – 3 blue and 5 red
10 squares – 6 blue, 4 red
Total pieces = 10 + 8 = 18
Now,
Probability that lost piece is blue square
= (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑏𝑙𝑢𝑒 𝑠𝑞𝑢𝑎𝑟𝑒𝑠)/(𝑇𝑜𝑡𝑎𝑙 𝑝𝑖𝑒𝑐𝑒𝑠)
= 6/18
= 𝟏/𝟑
So, the correct answer is (c)
Question 5 Find the probability that lost piece is traingle of Red colour. (A) 4/9 (B) 5/9 (C) 1/3 (D) 5/18Now, we have
8 triangles – 3 blue and 5 red
10 squares – 6 blue, 4 red
Total pieces = 10 + 8 = 18
Now,
Probability that lost piece is red triangle
= (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑟𝑒𝑑 𝑡𝑟𝑖𝑎𝑛𝑔𝑙𝑒)/(𝑇𝑜𝑡𝑎𝑙 𝑝𝑖𝑒𝑐𝑒𝑠)
= 𝟓/𝟏𝟖
So, the correct answer is (d)

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.