Question

The average height of a class of 18 students is 105 cm. After
the arrival of 7 new students the average decreases by 5cm
Find sum of the heights of all the students in the class.
for God Sake tell the correct answer​

Answer 1

Answer:

700

Step-by-step explanation:

Given:

Average height of a class of 18 students =105cms.

Total average of height of 18 students is = 18 × 105 = 1890.

Solution:

Seven new students added, then

Total students is = 18 old students+ seven new students. = 25 students (total).

If average decreases by 5cms,

Then 105 - 5 = 100 cms.

Now heights of newly added seven students is = 7 * 105 - 5 = 7 × 100.= 700cms.

Thanks : ]

Answer 2

Answer:

Total number of students = 8+7

Average height of the 25 students = 105-5=100cm.

sum of height of all students = 100×25= 2500 cm.

Hence, the sum of the heights of all students in the class = 2500cm