Question
In a 1-kilometre race, A can beat B by 30 metres, while in a 500-metre race B can beat C by 25 metres. By how many metres will A beat C in a 100-metre race?
-
7.85
-
7.25
-
7.15
-
7.03
Solution
A.
7.85
When A runs 1000 metre, B runs 970 metre.
∴ When A runs 100 m, B runs 97 metre.
When B runs 500 metre, C runs 475 metre
∴ When B runs 97 metre, C runs,
∴ A will beat C by (100 - 92.15) = 7.85 metre.
