Karan and Arjun run a 100-metre Race, Where Karan Beats Arjun by 10 metres GMAT Problem Solving

Question: Karan and Arjun run a 100-metre race, where Karan beats Arjun by 10 metres. To do a favour to Arjun, Karan starts 10 metres behind the starting line in a second 100-metre race. They both run at their earlier speeds. Which of the following is true in connection with the second race?

(A) Karan & Arjun reach finishing line together.
(B) Arjun beats Karan by 1 metre.
(C) Arjun beats Karan by 11 metres.
(D) Karan beats Arjun by 1 metre.
(E) Karan beats Arjun by 2 metre.

Correct Answer: D
Solution and Explanation:
Approach Solution 1:

Given:

Karan and Arjun run a 100 metres race, where Karan beats Arjun by 10 metres.
Karan starts 10 metres behind the starting line in a second 100 metre race. They both run at their earlier speeds.

Formula used:

Speed is directly proportional to the Distance

Calculation:

Karan and Arjun run a 100 metres race, where Karan beats Arjun by 10 metres.

When karan runs 100m and Arjun runs 90 m
⇒ Distance ratio = 100 : 90
⇒ Speed ratio = 100 : 90
⇒ 10 : 9

Karan starts 10 metres behind the starting line in a second 100 metre race.

Karan has runs 110 m

When Race is finish,
Arjun runs 9/10 of the karan runs
⇒ (9/10)× 110
⇒ 99 m Karan beats Arjun by 100 - 99
⇒ 1 m

Therefore, Karan beats Arjun by 1 m

Approach Solution 2:
In the 1st race when Karan runs 100 metres, Arjun runs only 90 metres.
Hence, the ratio of speeds of Arjun and Karan is 90 : 100 = 9 : 10
In the 2nd race, Karan has run 110 metres.
When he finishes the race, Arjun would have run 9/10×110= 99 metre
Therefore, Karan beats Arjun by 1 metre

Approach Solution 3:
^VK/^VA= 100/(100−10)= 10/9
Time taken to cover 110m by Karan= 110/10x= 11/x
Distance covered by Arjun in 11/x time= 9x*(11/x)= 99m
Karan beats Arjun by (100-99)= 1m

“Karan and Arjun run a 100-metre race, where Karan beats Arjun by 10”- is a topic of the GMAT Quantitative reasoning section of GMAT. To solve GMAT Problem Solving questions a student must have knowledge about a good amount of qualitative skills. GMAT Quant practice papers improve the mathematical knowledge of the candidates as it represents multiple sorts of quantitative problems.

Suggested GMAT Problem Solving Questions

Fees Structure

CategoryState
General15556

In case of any inaccuracy, Notify Us! 

Comments


No Comments To Show