text: const CustomError = require("../extensions/custom-error");
  
  const MODERN_ACTIVITY= 15;
  const HALF_LIFE_PERIOD= 5730;
  
  module.exports = function dateSample(sampleActivity ) {
    
  if (typeof sampleActivity != 'string') return false;
  sampleActivity = Number(sampleActivity);
    if(sampleActivity > 0 && sampleActivity <= 15  ){
      let k = 0.693 / HALF_LIFE_PERIOD;
      let t = Math.ceil(Math.log(MODERN_ACTIVITY / sampleActivity) / k);
        if(t <0) return false;
        return t;
      } else return false; 
  
  
  };
  