Question
Train 'A' having a speed of 20 m/s can cross a man in 7
seconds. The length of train 'B' is 40 metres more than the length of 'A'. If the speed of 'B' is 30 m/sec and both trains are travelling towards each other, then find the time taken by them to cross each other.Solution
Length of train 'A' = 20 × 7 = 140 metres
Length of train 'B' = 140 + 40 = 180 metres
Relative speed = 20 + 30 = 50 m/sec
Required time = (140 + 180) ÷ 50 = 320 ÷ 50 = 6.4 seconds
The average weight of 8 students in a class is 35 kg. If the weight of 4 teachers is also included, then the new average weight of each person (teacher ...
In an examination, the average marks obtained by the students is 75. After correcting the quantitative mistakes, the average of 100 students is reduced ...
Four numbers are arranged in ascending order. When the first two numbers are increased by the number equal to their position, and the last two numbers i...
The average of a set of 's' numbers is 24. If 40 is added to the set, then the average of the set becomes 24.4. Find the value of '4 X (s - 14)'.
5 positive numbers are written on a piece of paper. Sum of first 3 numbers is 55 and ratio of the 4th and the 5th number is 2:3. If difference between t...
The average number of books sold by Viren in first 5 months is 3800 and in first 6 months is 4600. If the number of books sold by him in 7th ...
Average marks scored by each boy in a class were 75, whereas that by each girl were 85. If the number of boys is 50% more than the number of girls, then...
An English-based company has 625 men and 625 female employees in a collaborative project. The average attendance of all employees is 74 calls per day. O...
- Average of 10 quantities is 35. If two extra quantities are added whose average is 'x', the new average rises by 10%. Find the value of 'x'.
Average marks scored by Vineet in five subjects are 70. The average marks scored by him (excluding his highest and lowest marks) are 50 and lowest marks...
Relevant for Exams:
