Mr. Alex usually starts at 9:00am and reaches his office jus

Solution:
Statement (2) is nothing but an ordinary saying. At same speed if you start 10 minutes early you will reach 10 minutes early and it’s not a surprise. So it’s nothing but to waste time. So not sufficient.

Before discussing over statement (1), one thing we have to realize clearly.

If we start late and then still want to reach in time then we have to move faster and save time in respect to the regular duration.

Formula, S = Vt , where S=distance , V= velocity and t = time.

For regular speed, journey starts from just 9am. We have the original equation,
S = Vt
Or, t = S/V (Regular time)

Last Wednesday (starting at 9:30am), drove 25% faster over the same distance,
so now the time, T= S/1.25V (here , 25% faster velocity = 1.25V)

After making 30 minutes late Mr. Alex still wants to reach in time, so he has to move faster and save at least 30 minutes in respect of the regular time (because he is 30 minutes late already, he has to cover this time) .

Now he can save time = S/V - S/1.25V = S/5V .
This time value S/5V has to be more than 30 minutes. Because this is his savings and he is already 30 minutes late. If S/5V > 30 minutes then only it will be possible for him to reach in time.

Now S/5V > 30
Or, S/V > 150 ………………………………..(eq1)

From statement (1) ,we know he started 20 minutes early {REMIND IT: HE STARTED 20MINUTES EARLY, SO HE DROVE 20 MINUTES LONGER HERE IN THIS CASE}, drove 20% slower than his regular speed and reached in time.



So , time = S/0.8V (more time than the regular) (20% slower speed = 80% of V = 0.8V)

Now the time difference between the regular and the above (S/0.8V) time
is = S/0.8V – S/V = S/4V = 20 minutes.
Or, S/V = 80 minutes.

From eq1, we know in order to reach in time S/V has to be greater than 150 ,
which is S/V > 150 .
But from statement(1) we found that S/V=80 .
So Mr. Alex didn’t reach office in time that day.

Statement(1) is sufficient alone. Answer is (A) .