Question

plz. dear solve this maths hard question b.brainliest yr answer awrded​

Answer 1

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