Dear student, you might have not paid enough attention to the word "

**independently**" in the question statement. A lot of times just one word in the question statement can change the entire meaning and as the result the correct answer choice.

**Quote:**

(25 times 4 is NOT 100)

In fact 25 × 4 = 100.

**Quote:**

Crew A will produce 6 cars in 120 mins. Crew B will produce 4.8 cars in 120 mins.

So in 120 minutes crew A will produce 6 COMPLETE cars, while crew B will produce 4 COMPLETE cars (+ 1 UNCOMPLETED car). Therefore they will produce 10 COMPLETE cars in 120 minutes.

**Quote:**

The combined amount of time required here is 111 1/9 mins.

How many COMPLETE cars will they produce in 111 1/9 minutes?

Crew A will produce 5 COMPLETE cars (+ 1 uncompleted)

Crew B will produce 4 COMPLETE cars (+ 1 uncompleted)

So in 111 1/9 minutes they will produce only 9 COMPLETE cars, while the question statement requires 10 complete cars to be produced.