How to solve “sumOfTwo” in CodeFights

The Problem:

You have two integer arrays, a and b, and an integer target value v. Determine whether there is a pair of numbers, where one number is taken from a and the other from b, that can be added together to get a sum of v. Return true if such a pair exists, otherwise return false.ExampleFor a = [1, 2, 3], b = [10, 20, 30, 40], and v = 42, the output should be
sumOfTwo(a, b, v) = true.

Gintama. WP