55. Среднее арифметическое чисел 5, x,15 равно 10. Найдите x.

5
10
15
8
12
56.Choose the true statement according to the listening 1.Nobody loves oranges 2.Some oranges don’t have any seeds 3.Orange trees have small white flowers 4.In the past oranges were very big
1,2
2,3
1,3
3,4
1,4