Apex Triggers

Triggers.apxt

trigger DmlTriggerBulk on Account(after update) {

    List<Opportunity> relatedOpps = [SELECT Id,Name,Probability FROM
        Opportunity WHERE AccountId IN :Trigger.New];
          
    List<Opportunity> oppsToUpdate = new List<Opportunity>();
    for(Opportunity opp : relatedOpps) {      
        if ((opp.Probability >= 50) && (opp.Probability < 100)) {
            opp.Description = 'New description for opportunity.';
            oppsToUpdate.add(opp);
        }
    }
    update oppsToUpdate;
}