Question
Two trains of same length are running in parallel tracks
in the same direction with speed 64 km/hr and 100 km/hr respectively. The latter completely crosses the former in 20 seconds. Find the length of each train (in m).Solution
When two trains cross each other, they cover distance equal to the sum of their lengths with relative speed.  Let's take length of each train = x So, total length of both trains = 2x Relative speed = (100 – 64) × (5/18) = 10 m/sec. ∴  Total length = Time × Relative speed  ⇒  2x = (20 × 10) ⇒  x = 100 m
28, 52, 84, 124, 172, ?.
Simplify the expression -:
If log₃(2x + 3) = 2 + log₃(x – 1), find x.
If f(g(x))= x, where f and g are inverses of each other and f’(x) = 1/(1+x ² ), then g’(x) equals:
? = 234.87 + 32.14% of (59.88 x 70.04)
A bag contains coins of ₹1, ₹2, and ₹5 denominations in the ratio 3:2:1. If the total amount in the bag is ₹240, find the number of ₹2 coins.
If a person invests ₹50,000 in a scheme offering a compound interest of 5% per annum, calculate the total amount he will have after 3 years. Assume th...
P earns Rs. 12,000 per month. He spends 40% of his income on rent, 25% of the remaining amount on food, and saves the rest. Q sav...
Find the distance between the points (2, 5) and (7, 1).