It takes robert one minute to gather his materials to begin his homework, then an addictional minute for each problem on his assignment. If it takes him 20 minutes to complete the assignment, how many problems were on his assignment?
so 1 minute to gather 1 minute per problem so assumming the gathering time is included 1+1timesnumberofproblems=20 subtract 1 from both sides 1timesnumberofproblems=19 numberofproblems=19
