Total messages received by Soham on his birthday = 40
Percentage of messages received for birthday greetings = 90%
Suppose Soham got A number of birthday greetings.
......(Multiplying both sides by 40)
∴ A = 36
∴ Number of messages received other than birthday greetings
= total messages received – total number of birthday greetings
= 40 – 36 = 4
∴ The number of messages received other than birthday greetings is 4.
