Question

11. A student starts from his house with a speed of 12 kmh-!
and reaches the school 3 min late. Next day he increases
speed by 1 kmh-' and reaches the school 3 min earlier.
Find the distance between his house and office.
​

Answer 1

Answer:

28 km.

Explanation:

Mark me as brainliest

Answer 2

Answer:

why don't you rate me brainly

Explanation:

Whenever 2 speeds are given in the question S1 and S2 , the fastest way of solving the question is by using this formula

S1 X S2 = D X ( S1 ~ S2 ) / ( T1 ~ T2 )

Here

S1 = 2.5 km/hr

S2 = 4.5 km/hr

T1 = t + 6/60 hr

T2 = t - 10/60 hr

Let D be the distance , Now

S1 X S2 = D X ( S2 - S1 ) / ( T1 - T2 )

[ Note: S2 - S1 because S2 > S1 AND T1 - T2 because T1 > T2 ]

Now putting the values in the above formula

2.5 X 4.5 = D X ( 4.5 - 2.5 ) / ( t + 6/60 - t + 10/60 )

D = 2.5 X 4.5 X 16 / 2 X 60

D = 1.5 kms