plz. dear solve this maths hard question b.brainliest yr answer awrded
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plz. dear solve this maths hard question b.brainliest yr answer awrded
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Answer:
15 or 8 km / hr. May be on substituting the values of an in situation you may get one from these.
Step-by-step explanation:
Let the speed of Subash be a km / hr.
Since speed of Uday is 5 km / kr more than the speed of Subash, let it be ( a + 5 ) km / hr.
So, let, { unit for speed is km / hr & for time it's hr & for distance it's km, not being written again & again }
Speed of Subash is a
Speed of Uday is a + 5
Assuming that both of them come to the same office :
•----distance by subash-----O---------distance by uday----•
Here,
distance covered by Subash is 12 km & distance by Uday is 48 km { as given in question }
•--------12 km------Office--------------48km----------•
Speed of Subash = a
= > distance / time = a
= > 12 / time = a
= > time = 12 / a ...( 1 )
Speed of Uday = a + 5
= > 48 / time = a + 5
= > time = 48 / ( a + 5 )
Given, here,
= > Time by Uday = time by Subash + 2
= > 48 / ( a + 5 ) = 12 / a + 2
= > 48 / ( a + 5 ) - 12 / a = 2
= > [ 48a - 12a - 60 ] / a( a + 5 ) = 2
= > [ 36a - 60 ] = 2a( a + 5 )
= > 18a - 30 = a( a + 5 )
= > 18a - 30 = a^2 + 5a
= > a^2 - 13a + 30 = 0
= > a^2 - 10a - 3a + 30 = 0
= > a( a - 10 ) - 3( a - 10 ) = 0
= > ( a - 3 ) ( a - 10 ) = 0
= > a = 3 or 10
Hence speed of Uday is a + 5 = 3 + 5 = 8 km / hr or 10 + 5 = 15 km / hr