Forty students from five grades brought 50 candies for the “Trick or Treat” game in a Halloween party. It is known that students from the same grade brought an equal number of candies, while students from different grades brought different numbers of candies. How many students brought exactly one candy? help meplease

James wrote four tests with a maximum score of 100 in each one. The average mark he obtained on these tests was 88. What is the lowest score he could have achieved on one of these tests?

find the least number wich when divided by15,18,9 and 12 leaves the remainder of 5 in each case