Question

1
Running at an average speed of 40 km/hr, a bus completes a journey in 4(1/2)
How much time will the return journey take if the speed is increased to 45 km/hr
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Answer 1

ANSWER = 4 hr

$\huge\sf\red{\underline{\underline{Given ;- }}}$

A bus completes a journey in 4 and half hours at an average speed of 40 km/h

$\huge\sf\orange{\underline{\underline{to \: find;- }}}$

Time taken by the bus to complete journey at 45 km/hr

$\huge\sf\blue{\underline{\underline{formulas \: used;- }}}$

$\boxed{ \sf \: speed = \frac{distance }{time}} \:$

$\huge\sf\green{\underline{\underline{ answer;- }}}$

speed = 40 km/hr

= 40 × 5 / 18

= 11.1 m/s

time = 4.5 hour

= 4.5 × 360

= 1620 s

distance = speed × time

= 11.1 × 1620

= 17982 m

now speed = 45 km/h

= 12.5 m/s

time = distance / speed

= 17982 / 12.5

= 1438 . 56 s

= 3.99 hr ≈ 4 hr