4) mapOf<String, Int>("Mouhamed" to 21, "ali" to 25, "Papi" to 29) setOf<String>("one", "two", "three") val mutableList: MutableList<Int> = mutableListOf(1, 2, 3, 4) mutableMapOf("Mouhamed" to 21, "ali" to 25, "Papi" to 29) mutableSetOf("one", "two", "three") val list = listOf(1, 2, 3, 4) val newList = list.map { it * 2 }.filter { it > 2 }