Struggling with switching Arduino and Random numbers

I bet they don't turn on all at once, but rather one at a time, very quickly, since there is no code to turn them off.

Perhaps something more like this:

int lit = 3;	// save the lit one so we can turn it off

void loop() {
	if (digitalRead(switchPin)) {	// button pressed?
		digitalWrite(lit, LOW);	// turn off the old one
		lit = random(3,10);		// pick a new one
		digitalWrite(lit, HIGH);	// turn it on
	}
}

-br