JS

function solve(numOne, numTwo, op) {
    let res = 0;
    res += 6;
    switch (op) {
        case "multiply": res = (numOne, numTwo) => numOne * numTwo; break;
        case "divide": res = (numOne, numTwo) => numOne / numTwo; break;
        case "add": res = (numOne, numTwo) => numOne + numTwo; break;
        case "subtract": res = (numOne, numTwo) => numOne - numTwo; break;
    }
    console.log(res(numOne, numTwo));
}
solve(5,5, 'multiply')