Question
A solid rectangular parallelepiped (cuboid) has
dimensions 10 cm × 8 cm × 6 cm. It is melted and cast into small cubes each of side 2 cm. How many such cubes are formed, and what is the total surface area of all the cubes together?Solution
ATQ, Volume of cuboid = 10 × 8 × 6 = 480 cm³ Volume of one cube = 2³ = 8 cm³ Number of cubes = 480 / 8 = 60 Surface area of one cube = 6 × (2²) = 6 × 4 = 24 cm² Total surface area = 60 × 24 = 1440 cm²
A car travels at a speed of 60 km/hr for 2 hours and then at 40 km/hr for 3 hours. Find the total distance travelled.
The distance between two stations is 1520 km. Train A takes 9 hours longer than Train B to cover this distance. If Train B travels 72 km/h faster than T...
A man travels some distance at a speed of 36 km/hr and returns at a speed of 27 km/hr. If the total time taken by him is 2 hrs 20 min, the distance is <...
Rajesh drove at the speed 100 km/hr from his home to a resort. While returning he got struck in traffic and took 6 more hrs; he could drive only at the ...
- Riya travels 45.5 km in 2 hours and 30 minutes. How much distance will she cover in 4 hours if she increases her speed by 3 km/h?
Ajay and Vishal left the place ‘X’ with different speeds which are in the ratio 9:4 respectively. Ajay left the place 30 seconds after Vishal. If af...
‘I’ and ‘J’ are going from place ‘V’ to place ‘W’, which is 1350 km apart. If ‘I’ started 3 hours after ‘J’ but both of them rea...
Train M crosses a platform in 60 seconds and overtakes a man running in the opposite direction at 12 km/h in 30 seconds. Train N passes Train M, which i...
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...
- The running speeds of athletes I and J are 36 km/hr and 48 km/hr respectively. If I runs 24 km less than J in the same time, then what is the distance run ...
