Make a Multiplier

A function can build another function and return it. The inner function remembers the variables of the function that made it, even after that function has finished. This is called a closure.

Write make_multiplier(n) that returns a new function. The new function takes one argument x and returns x * n.

Examples

double = make_multiplier(2)
triple = make_multiplier(3)
double(21)                 # returns 42
triple(5)                  # returns 15
make_multiplier(3)('ab')   # returns 'ababab'

Each new function keeps its own n: making triple does not change double.