If A train takes 1 hr to go from one station to another. It travels at a speed of 30 km hr for first half hour and at a speed of 50 km hr for the next half hour. Find the average speed of the train?

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Solution

Dear Student,
$A v e r a g e s p e e d = \frac{T o t a l d i s \tan c e}{T o t a l t i m e t a k e n} D u r i n g t h e f i r s t h a l f h o u r, t_{1} = \frac{1}{2} h : d i s \tan c e t r a v e l l e d, d_{1} = v_{1} \times t_{1} = 30 \frac{k m}{h} \times \frac{1}{2} h = 15 k m . D u r i n g t h e s e c o n d h a l f h o u r, t_{2} = \frac{1}{2} h : d i s \tan c e t r a v e l l e d, d_{2} = v_{2} \times t_{2} = 50 \frac{k m}{h} \times \frac{1}{2} h = 25 k m T o t a l d i s \tan c e t r a v e l l e d, d = d_{1} + d_{2} = 40 k m T o t a l t i m e t a k e n, t = t_{1} + t_{2} = 1 h A v e r a g e s p e e d = \frac{40 k m}{1 h} = 40 \frac{k m}{h} R e g a r d s,$

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