gistfile1.txt

package main

import (
	"fmt"
	"math/rand"
)

func main() {
	t := 0
	i := 0
	for ; i < 1e7; i++ {
		if rand.Intn(100)+1 <= 75 {
			t++
		}
	}
	fmt.Printf("%0.3f\n", float64(t)/float64(i))
}