Aravind Bt: Tutoring for Knowledge Excellence

Answer

D. Power

Answer

Given P = Rs. 500 and A = Rs. 583.20 in 2 years compounded annually.

A divided by P gives us 1.1664. Square root of 11664 is 108; hence, square root of 1.1664 should be 1.08. Therefore, 500 has become 583.20 in 2 years at the rate of 8 percent compounded annually.

As per the question, the new rate of interest will be 2 percentage points more i.e. 10 percent pa. Therefore, Rs. 500 will become 550 in one year.

Answer

Given: Speed of stream = 1 kmph

Speed of man's boat in still water = 5 kmph.

Therefore,

Effective speed of man's boat when rowing downstream (in the direction of flow of stream) = (5+1) kmph = 6 kmph and

Effective speed of man's boat when rowing upstream (against the direction of flow of stream) = (5-1) kmph = 4 kmph.

Total time taken is 75 minutes i.e. 1 hour 15 minutes. From this, we can eliminate option (A) since rowing 6 km downstream itself will take 1 hour and quite obviously, rowing 6 km upstream cannot happen in the remaining 15 minutes.

If we consider option (C) i.e. 4 km - 4 km is travelled in (2/3) hours i.e. 40 minutes downstream and 4 km upstream is travelled in 1 hour i.e. 60 minutes. Therefore, total time is 100 minutes, which is not possible. Therefore, option (C) and (E) both can be ruled out.

Option (D) - 3 km is travelled in (1/2) hours i.e. 30 mins when travelling downstream and 3 km is travelled in (3/4) hours i.e. 45 minutes when travelling upstream. Total time = (30+45) = 75 minutes.

Hence, optino (D) is the right answer.

Answer

Whatever sums A and B respectively have borrowed, both of them end up paying a total Simple Interest of 20 percent of their respective principals. But, the problem says that A's interest is double of B's interest, by which we can infer that the principal of A is double the principal of B. Hence, Rs. 30,000 has to be split up in the ratio of 2:1.

Therefore, the principal borrowed by A = Rs. 20,000 which is option (B)

Answer

Since the trains are moving towards each other, their relative speed = (16+21) = 37 kmph. Also, in this case, both the trains travel for the same period of time; hence, the respective distances travelled by them by the time they meet will be in the ratio of their individual speeds.

• Remember, when T is constant, D is directly proportional to S. Hence, (D1/D2) = (S1/S2).

Hence, (Da/Db) = (Sa/Sb) i.e. (Da/Db) = 16/21. Let Da = 16k and Db = 21k.

Given that one train travelled 60 km more than the other. Hence, 21k - 16k = 60

i.e. 5k = 60.

Therefore, k = 12.

Total distance between the two stations is nothing but the distances travelled by the respective trains till the meeting point i.e. (16k + 21k) = 37k = 37 * 12 = 444 km.

Hence, option (B)

Answer

SP of laptop = 90% of MP (because of 10% discount)

SP of laptop = (9/10) * 1050

SP of laptop = 9 * 105

SP of laptop = 945

Now, SP of laptop also = 125% of CP (because a 25% profit was made and remember, profit is always calculated as a percentage of CP).

Therefore, 945 = (5/4) CP.

Therefore, CP = (4/5) *945

CP = 4 * 189

CP = 756

Hence, option (B)