A truck covers a distance of 330 km at the speed of 30 km/hr. What is the average speed of a car which travels a distance of 110 km more than the truck in the same time?
(a) 42 km/hr
(b) 48 km/hr
(c) 39 km/hr
(d) 38 km/hr
(e) None of these
Solution: (e)
Total time taken by truck = \(\displaystyle \frac{{330}}{{30}}=11hrs\)
New distance = 330 + 110 = 440 km
Average speed of car = \(\displaystyle \frac{{440}}{{11}}=40km/hr\)
Anu walks 2.31 km in three weeks by walking an equal distance each day. How many metres does she walk each day?
(a) 110 m
(b) 90 m
(c) 140 m
(d) 120 m
(e) None of these
Solution: (a)
2.31 km = \(\displaystyle 2.31\times 1000=2310\) m
Total number of days = \(\displaystyle 3\times 7=21\)
Therefore, Distance covered by Anu each day
\(\displaystyle \frac{{2310}}{{21}}=110m\)
A 360-metre-long train cross a platform in 120 seconds. What is the speed of the train?
(a) 3 m/s
(b) 5 m/s
(c) 4.5 m/s
(d) Cannot be determined
(e) None of these
Solution: (d)
It can’t be determined because the length of the platform is not given.
A truck covers a distance of 640 km in 10 hr. A car covers the same distance in 8 hr. What is the ratio of the speed of the truck to that of the car?
(a) 3 : 4
(b) 1 : 2
(c) 5 : 6
(d) 6 : 7
(e) None of these
Solution: (e)
Speed of the truck = \(\displaystyle \frac{{640}}{{10}}=64km/hr\)
Speed of the car = \(\displaystyle \frac{{640}}{8}=80km/hr\)
Ratio = \(\displaystyle \frac{{64}}{{80}}=\frac{4}{5}=4:5\)
A man riding a bicycle completes one lap of a circular field along its circumference at the speed of 79.2 km/hr in 2 minutes 40 seconds. What is the area of the field?
Area of circular field = \(\displaystyle \pi {{r}^{2}}=\frac{{22}}{7}\times {{(560)}^{2}}\) \(\displaystyle \frac{{22}}{7}\times 560\times 560=985600{{m}^{2}}\)
