All Swift classes must inherit from which root class?

Not Required NSObject NSRootObject @ObjC

Swift is built on top of C and ____.

Java Python HTML Objective-C

Application in background & executing background tasks.Determine current state of Application.

Background state Not running state Inactive state Suspended state

Multitasking in iOS was introduced in which version?

iOS 4.0 iOS 2.0 iOS 6.0 iOS 7.0

Given the code below, what data type does i have?let i = 10.2

Double char float var