Question
Three numbers are in the ratio 3:5:6. If the sum of
their squares is 630, then the numbers are:Solution
Let the numbers be 3x, 5x and 6x respectively. ⇒ (3x)2 + (5x)2 + (6x)2 = 630 ⇒ 9x2 + 25x2 + 36x2 = 630 ⇒ 70x2 = 630 ⇒ x2 = 9 ⇒ x = 3 ∴ Numbers are 9, 15 and 18.
A car travels from point A to point B in 4 hours, covering a distance of 180 km. On the return journey, the speed is reduced by 20%. How much time does ...
A car travels from point A to point B at an average speed of 80 km/h. On the return journey from point B to point A, its average speed decreases by 25% ...
A car travels 50 km at a speed of 25 km/h and the next 80 km at a speed of 40 km/h. What is the average speed of the car for the entire journey?
A man travels some distance at a speed of 16 km/hr and returns at a speed of 8 km/hr. If the total time taken by him is 3 hrs 45 min, the distance is
Time taken by a boat to travel certain distance in upstream direction is twice the time taken by the boat to cover same distance in downstream direction...
If a car runs at 36 km/hr, it reaches its destination late by 15 minutes but if runs at 45 km/hr it is late by 9 minutes. What is the correct time for t...
A, B, and C run around a Circular track starting from the same point simultaneously and in the same direction at 6 km/h, 12 km/h, and 18 km/h respect...
A train covers a certain distance at a speed of 36 km/h and the next same distance with a speed of 45 km/h and the next same distance with a speed of 60...
A sprinter is 600 metres behind another runner and begins a chase at a speed of 22 m/s. If the runner ahead is moving at 14 m/s, find out the time it wi...
A and B are travelling towards each other with a speed of 10 km/hr and 20 km/hr. They started at same time and A covered 15 km less distance than B befo...
