Question
The average of 10 numbers is 42. If the average of the
first 4 numbers is 24 and the average of the last three numbers is 36, then what is the average of the remaining numbers?Solution
ATQ,
Sum of the 10 numbers = 10 × 42 = 420
Sum of the first 4 numbers = 4 × 24 = 96
Sum of the last 3 numbers = 3 × 36 = 108
Sum of the remaining numbers = 420 - 96 - 108 = 216
Required average = 216 / 3 = 72
A woman must travel 500 km in 10 hours. If she traveled the first 30% of the journey at a constant speed of 50 km/h, at what speed must she travel the r...
John cycles at 10 km/h to reach his destination at 2 PM. If he travels at 15 km/h, he will reach at 12 noon itself. At what speed should he travel to re...
A can complete a piece of work in 12 days, and B can complete the same work in 16 days. They work together for 4 days, and then A leaves. How many more ...
Resham travels 60 km at 20 km/h by cycle, 120 km at 60 km/h by car, and the remaining 10 km on foot at 2.5 km/h. Find her average speed for the whole jo...
1470 metres long train crosses a man who is moving in the same direction with a certain speed, in 30 seconds. If the same train can cross a tree in 7 se...
How much time a train 120 metres long running at the speed of 36 km/hr will take to cross a bridge 130 metres in length?
A man travels some distance at a speed of 15 km/hr and returns at a speed of 9 km/hr. If the total time taken by him is 2 hrs 40 min, the distance is
- A car is 2,400 metres ahead of a truck when the truck starts chasing at a speed of 32 m/s. The car is moving at 24 m/s. How much time will the truck take t...
A and B can complete a work in 20 and 30 days, respectively. If they work together for 10 days and then A leaves, how many more days will B take to fini...
- Two cars, ‘X’ and ‘Y’, started from towns ‘M’ and ‘N’ towards each other at the same time. When they met after 6 hours, car ‘Y’ had tra...
Relevant for Exams:
