Question

One-tenth of the bikes in a parking lot are RED.another bike arrives and now one-ninth of the bikes are RED.how many red bikes are there and how many total bikes are there?

Answer 1

Answer:

Step-by-step explanation:

Answer 2

After the arrival of another bike, the number of bikes in the parking lot became 81, out of which the red bikes were 9.

Step-by-step explanation:

Let the number of bikes in the parking lot originally be x.

Let the number of the red bikes originally are y

Based on Eq 1:

1/10 x = y

Thus; x = 10y ………………. (1)

Case 2 states that the number of red bikes becomes 1/9 after another bie arrives.

Thus, the bike which came must be red since it increased the ratio of the red bikes.

So;

1/9 (x+1) = y + 1

9 (y + 1) =  x + 1 ……………..(2)

Substituting Eq 1 in Eq 2

9 (y + 1) = 10y + 1

9 y + 9 = 10 y + 1

Thus;

Y = 8

Hence;

X = 10y = 10 x 8 = 80

Thus, the original number of bikes in the parking lot were 80, out of which 8 were red bikes.

After the arrival of another bike, the number of bikes in the parking lot became 81, out of which the red bikes were 9.