Ateacher always arranged the content0 of each lessons to year 10 as teaching and practising learnt skills in the ratio 2: 3. α if a lesson lasted 35 minues how much teaching would he do? b) if he decided to teach for 30 minutes how long would the lesson be?

The decibel level of sound is 50 db greater on a busy street than in a quiet room where the intensity of sound is watt/m2. the level of sound in the quiet room is db, and the intensity of sound in the busy street is watt/m2. use the formula , where is the sound level in decibels, i is the intensity of sound, and is the smallest sound intensity that can be heard by the human ear (roughly equal to watts/m2).

Find the distance from the theater to the library. leave your answer in simplest radical form if necessary. 12 √12 74 √74

He ! a group of farmers planned to clean 80 acres of wheat per day to finish the work on schedule. right before the work started, they received a new piece of machinery that them clean 10 more acres per day than originally planned. as a result of increased productivity in the last day before the deadline they only had to clean 30 acres. how many acres of wheat did the group of farmers have to clean?