Question

Jim travels the first 3 hours of his journey at 60 mph speed and the remaining 5 hours
at 24 mph speed. What is the average speed of Jim's travel in mph?
O 36 mph
O 37.5 mph
0 42 mph
O 42.5 mph
O O 48 mph​

Answer 1

Given : Jim travels the first 3 hours of his journey at 60 mph speed and the remaining 5 hours at 24 mph speed.

Need To Find : Average Speed of Jim's travel in mph .

⠀⠀⠀⠀⠀━━━━━━━━━━━━━━━━━━━⠀

⠀⠀⠀⠀Finding Distance Travelled in both case of speed :

⠀Finding Distance Travelled in first 3 hrs at the speed of 60 mph :

$\dag\:\:\it{ As,\:We\:know\:that\::}$

$\qquad \dag\:\:\bigg\lgroup \sf{ Distance \:: Speed \times Time }\bigg\rgroup$

⠀⠀⠀⠀Here , Speed is 60 mph & Time is 3 hrs .

⠀⠀⠀⠀⠀⠀$\underline {\boldsymbol{\star\:Now \: By \: Substituting \: the \: Given \: Values \::}}$

$\qquad \longmapsto \sf{ Distance = 60 \times 3 }$

$\qquad \longmapsto \frak{\underline{\purple{\:Distance = 180km }} }$

Therefore,

⠀⠀⠀⠀⠀$\therefore {\underline{ \mathrm {\:Distance \:Travelled \:in\:first\:3\:hours \:is\:\bf{180\: km}}}}$

⠀Finding Distance Travelled in remaining 5 hrs at the speed of 24 mph :

$\dag\:\:\it{ As,\:We\:know\:that\::}$

$\qquad \dag\:\:\bigg\lgroup \sf{ Distance \:: Speed \times Time }\bigg\rgroup$

⠀⠀⠀⠀Here , Speed is 24 mph & Time is 5 hrs .

⠀⠀⠀⠀⠀⠀$\underline {\boldsymbol{\star\:Now \: By \: Substituting \: the \: Given \: Values \::}}$

$\qquad \longmapsto \sf{ Distance = 24 \times 5 }$

$\qquad \longmapsto \frak{\underline{\purple{\:Distance = 120 km }} }$

Therefore,

⠀⠀⠀⠀⠀$\therefore {\underline{ \mathrm {\:Distance \:Travelled \:in\:remaining \:8\:hours \:is\:\bf{120\: km}}}}$

⠀⠀⠀⠀⠀━━━━━━━━━━━━━━━━━━━⠀

⠀⠀⠀⠀Now , Finding Average Speed :

$\dag\:\:\it{ As,\:We\:know\:that\::}$

$\qquad \dag\:\:\bigg\lgroup \sf{ Average \:Speed\:\:: \dfrac{Total\;Distance \:Travelled\:}{Total\:Time\:Taken}}\bigg\rgroup$

Here ,

⠀⠀⠀⠀Total Distance Travelled = Distance Travelled in first 3 hrs + Distance Travelled ⠀⠀⠀⠀in remaining 5 hrs .

⠀⠀⠀⠀Total Distance Travelled = 120 km + 180 km

⠀⠀⠀⠀Total Distance Covered in journey = 300 km .

⠀⠀&

⠀⠀⠀⠀Total Time Taken = 3hrs + 5 hrs

⠀⠀⠀⠀Total Time Taken = 8 hrs .

⠀⠀⠀⠀⠀⠀$\underline {\boldsymbol{\star\:Now \: By \: Substituting \: the \: Given \: Values \::}}$

$\qquad \longmapsto \sf { Average \:Speed = \dfrac{300}{8}}$

$\qquad \longmapsto \sf { Average \:Speed = \cancel {\dfrac{300}{8}}}$

$\qquad \longmapsto \frak{\underline{\purple{\:Average \:Spped\: = 37.5 mph }} }$

Therefore,

⠀⠀⠀⠀⠀$\therefore {\underline{ \mathrm {\:The\:Average \:Speed\:of\:Jim's\:travel \:is\:\bf{37.5\:mph}}}}$

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Answer 2

Answer:

Step-by-step explanation: