 
 <translate> Explanation: Sum of the ages of the students = 39×15 = 585
New average = 15 years 3 months = 15 + 1414 year
Sum of the ages of students and teacher = 40×15141514 = 40×614614 = 610
Teacher age = 610 – 585 = 25 years. <hau> Bayani: Jimlar shekarun dalibai = 39 × 15 = 585 Sabuwar matsakaici = 15 shekaru 3 watanni = 15 + 1414 shekara Jimlar shekarun ɗalibai da malami = 40 × 15141514 = 40 × 614614 = 610 Shekaru na malami = 610 <unk> 585 = shekaru 25. 