Question

A runner covers 20m in the first second. Every second thereafter he
covers 3/4 of the distance covered in the previous second How much
distance does he run in first 4 seconds ? give your answer to three decimal places​

Answer 1

Answer :

• 54.68m distance he run in first 4 seconds

Given :

• A runner covers 20m in the first second.
• Every second thereafter he covers 3/4 of the distance covered in the previous second

To find :

• How much distance does he run in first 4 seconds

Solution :

Given,A runner covers 20m in the first second. Every second thereafter he covers 3/4 of the distance covered in the previous second so,

》A runner covers distance in first second = 20m

》 A runner covers distance in second second = 20 × 3/4 = 15m

》A runner covers distance in third second = 15 × 3/4 = 45/4m

》A runner covers distance in fourth second = 45/4 × 3/4 = 135/16 m

And also Given that he covers total distance in four seconds so,

》20 + 15 + 45/4 + 135/16 m

》320 + 240 + 180 + 135 / 16

》875/16

》54.68 m

Hence, 54.68m distance he run in first 4 seconds