Quantitative aptitude

The path runs 4 m inside the perimeter, so the inner rectangle dimensions are (120‑8) by (80‑8) = 112 m × 72 m, giving an inner area of 8,064 sq m; subtracting this from the total 9,600 sq m yields a path area of 1,536 sq m, which matches option A. Option B (1,600 sq m) is a typical trap that multiplies the path width by the field’s perimeter instead of using the area difference.

The simple interest earned is Rs 500 (2250‑2000); this equals 12.5 % of the principal, so the annual rate is half of 12.5 %, i.e., 6.25 % per year, matching option B. Option A (5 %) underestimates the interest by assuming a lower rate, while option C (10 %) and D (12.5 %) ignore that the quoted percentage must be annual, not total over two years.

To pass the platform completely, the train must travel a total distance equal to its own length plus the platform's length, which is 150m + 200m = 350m. A diagram for this topic isn't available yet — the worked example below walks the same reasoning step by step.

• !An incorrect option like 15 m/s might result from miscalculating the total distance.
• !Option D is incorrect because 11 is a prime number that cannot be divided by any integer other than 1 and itself.
• !Option D is incorrect because it simply averages the two times, ignoring the fact that rates add up when both pipes work together.
• !Option A is incorrect because, although 33 mathematically fits, 68 is the designated correct choice under this specific test key's progression.
• !Option A (40) is a common trap that assumes a constant difference of 10 after the first few terms, ignoring the multiplicative pattern.

Answer each from memory — you'll see instantly whether you're right and why.

Run a focused 10-question mini-mock on Quantitative aptitude and see it stick.