Question 2 - Figure it out - Page 102 to 105 - Chapter 4 Class 7 - Expressions using Letter-Numbers (Ganita Prakash)

Transcript

Question 2 Pushpita sells two types of flowers on Independence day: champak and marigold. ‘p’ customers only bought champak, ‘q’ customers only bought marigold, and ‘r’ customers bought both. On the same day, she gave away a tiny national flag to every customer. How many flags did she give away that day? (a) p + q + r (b) p + q + 2r (c) 2 × (p + q + r) (d) p + q + r + 2 (e) p + q + r + 1 (f) 2 × (p + q)We can do it by an example also Say 2 customers bought champak, 3 customers bought marigold, 5 customers bought both Now, every customer got a national flag Thus, total flags = 2 + 3 + 5 Similarly, Total flags = p + q + r Thus, ‘p’ customers that bought champak also got a national flag ∴ Number of flags = p ‘a’ customers that bought marigold got a national flag ∴ Number of flags = q ‘r’ customers that bought flowers got a national flag ∴ Number of flags = r Therefore, Total flags = p + q + r So, option (a) is correct