1. A certain number of tennis balls were purchased for Rs.450. Five more balls could have been purchased in the same amount if each ball was cheaper by Rs.15. The number of balls purchased was:
2.Each boy contributede rupees equal to the number of girls and each girl contributed rupee equal to the number of boys in a class of 60 students. If the total contribution collected is Rs.1600, how many boys are there in the class?
3. A total of 324 coins of 20 paise and 25 paise make a sum of Rs.71. The number of 25 paise coints is
4. A student read 3/8 th of a book on one day and 4/5 th of the remainder on the another day. If there were 30 pages unread, how many pagers did the book contain?
5. In a group of buffaloes and ducks, the number of legs are 24 more than twice the number of heads. What is the number of buffaloes in the group?