Correct Answer - Option 3 : 11.05 meters
Given:
The average height of 7 ropes is 4.8 meters.
The average height of the first 5 ropes is 2.3 meters.
Formula Used:
Average = sum of total terms/ total number of terms
Calculation:
The average height of 7 ropes is 4.8 meters.
Average = sum of total terms/ total number of terms
⇒ 4.8 = Sum of the total height of 7 ropes / 7
⇒ Sum of the total height of 7 ropes = 4.8 × 7
⇒ Sum of the total height of 7 ropes = 33.6 meters.
The average height of the first 5 ropes is 2.3 meters.
⇒ 2.3 = Sum of the height of first 5 ropes / 5
⇒ Sum of the height of the first 5 ropes = 2.3 × 5
⇒ Sum of the height of the first 5 ropes = 11.5 meters.
⇒ Sum of the height of the last two ropes = 33.6 – 11.5
⇒ Sum of the height of the last two ropes = 22.1
Average = sum of total terms/ total number of terms
⇒ Average = 22.1 / 2
⇒ Average = 11.05
∴ The average height of the last two ropes is 11.05 meters