1.

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

• 8.75

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.