Сумма равна 120. среднее арифметическое = 5. Какое число надо прибавить, чтобы среднее арифметическое стало равно 7. Помогите пожалуйста!

«В олимпиаде по математике принимали участие 50 человек. 68% учеников решили мало задач. 75% оставшихся решили средне, а остальные – много задач. Сколько человек решило много задач?»

помогите пожалуйста!тут надо слова изменять по смыслу.вот текст:

Вариант 6 В11-В16 Christopher Wren

Sir Christopher Wren was the famous English architect.Thanks to his skills and experience the modern Londoners are proud of their capital.More than fifty new churches and a large number of houses were designed by Wren.The Bll—beauty-building which was designed by Wren in the Gothic style was St.Paul's Cathedral.

In the Great London Fire of 1066, 3000buildings, houses and 97 churches were destroyed.After the Fire,London wasB12—success- rebuilt,but the new houses were built of the stone and brick instead of wood.

The streets were made B13—wide- and open space was left for B14—attract— squares. An opportunity to plan the new city of London was given to Sir Christopher Wren.

Among B15—remark buildings which were built by Wren was St.Paul's Cathedral with its huge dome and rows of columns.lt is theB16—history building and is considered to be a fine specimen of Renaissance architecture.In one of its towers hangs one of the largest bells in the world.Great Paul,weihing about 17.5 tons.Nelson, Wellington and other great men of England are bured in the Cathedral.

свое собственное хокку(трехстишье).

З двох населених пунктів відстань між якими44, 62 км, виїхали одночасно двоє велосипедистів на зустріч один одному.Швидкість одного з них15 км\год, а швидкість другого становить 96% швидкомсті першого.Через скільки годин вони зустрінуться?