adding tricky js Questions collection

Author: rohan-paul

Javascript/Tricky-JS-Problems/Collection-of-Tricky-JS-Questlions.md

@@ -13,3 +13,7 @@
 #### Question: What is '6'+9
 
 **Answer**: 69. If one of the operands of the plus (+) operator is string it will convert other number or boolean to string and perform a concatenation. For the same reason, "2"+true will return "2true"
+
+#### Question: What is the value of 4+3+2+"1"
+
+**Answer**: 91 . The addition starts from the left, 4+3 results 7 and 7+2 is 9. So far, the plus operator is performing addition as both the operands are number. After that 9 + "1" where one of the operands is string and plus operator will perform concatenation.