Answer:
x = 210 minutes
Step-by-step explanation:
We can say that the previous race's finishing time was x and it was equal to 100% or 1.
We know that the current race's finishing time which is 189 minutes is 10% less than previous one's finishing time, so current race's finishing time can be said to be equal to 90% or 0.9.
Using the ratio and proportion, we can calculate the x to be,
1 : x
0.9 : 189
0.9 : 1 = 189 : x
0.9 * x = 1 * 189
x = 189 / 0.9
x = 210 minutes
