    // Define two arrays
    let a = [100, 200];
    let b = [[0, 3], [0, 4], [1, 5], [2, 5]];

    // Define empty array for result
    let result = [];

    // Loop over 'b', each time adding next element in 'result'
    for(let i in b) {
        result.push([a, b[i]]);
    }

    // In the end, 'result' contains the following array:
    // [[[100,200],[0,3]],[[100,200],[0,4]],[[100,200],[1,5]],[[100,200],[2,5]]]