Multiple choice

The average age of students and their teacher is 16 yr, the average age of the first four students is 19 yr and that of the last five is 10 yr. the teacher’s age is

  1. 36yr

  2. 34yr

  3. 30yr

  4. 28yr
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total people = 10 (9 students + 1 teacher). Total age = 16 * 10 = 160. Sum of 4 students = 19 * 4 = 76. Sum of 5 students = 10 * 5 = 50. Teacher's age = 160 - (76 + 50) = 160 - 126 = 34.

AI explanation

The question implies a class of 9 students plus 1 teacher, making the total count 10 people with a combined age of 10 multiplied by 16, which equals 160 years. The total age of the first four students is 4 multiplied by 19 to give 76, and the total age of the last five students is 5 multiplied by 10 to give 50, making the sum of all student ages 126 years. The teacher's age is the overall total sum minus the students' total sum, so 160 minus 126 equals 34 years.

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