In a 100 m race, Tina beats Mina by 20 m and in the same race Mina beats Rita by 10 m. By what distance does Tina beat Rita?

28 m

Correct option: B

Step-by-Step Explanation:

Step 1: Tina and Mina take part in a 100 m race.

The race result shows Tina beats Mina by 20 meters. This means, when Tina finishes 100 meters, Mina has only covered 80 meters.

Thus, the ratio of distances covered by Tina and Mina is:

Tina : Mina = 100 : 80 = 5 : 4

Step 2: Mina and Rita also compete in the same 100 m race.

In this race, Mina beats Rita by 10 meters. This implies, when Mina covers 100 meters, Rita has covered only 90 meters.

The ratio of distances covered by Mina and Rita is:

Mina : Rita = 100 : 90 = 10 : 9

Step 3: Combining the ratios to find the distance covered by Tina and Rita:

The combined ratio is calculated as:

Tina ÷ Mina × Mina ÷ Rita = 100 ÷ 80 × 100 ÷ 90

So, Tina : Rita = 100 : 72

Step 4: Calculating the distance by which Tina beats Rita:

If Tina covers 100 meters, Rita covers only 72 meters. Thus, Tina beats Rita by:

100 - 72 = 28 meters

Tina beats Rita by 28 meters.