Question

A man with 3/5 of his usual speed reaches the destination in2*1/2 hours late .find his usual time to reach the destination

Answer 1

Time = (5/2)*3/2 = 15/4 = 3 hours 45 minutes...

Answer 2

Answer:

His usual time to reach the destination is 3.75 hours

Step-by-step explanation:

Given,

With 3/5 of the usual speed,

Man reaches destination 2 1/2 hrs late, that is, 5/2 = 2.5 hrs

Let us suppose,

S = usual speed

T = usual time

D = distance to office,

So

$\frac{3}{5}$ * S = slower speed

T + 2.5 = time when walking at slower speed

Since the distance to the office is a constant, as distance remains the same whether he walks slower of faster,

So we can say ,

S * T = ( $\frac{3}{5}$ ) S * ( T + 2.5 )

ST = (  $\frac{3}{5}$ ) S * ( T + 2.5 )

ST = ( $\frac{3}{5}$ ) ST + 1.5 S

Divide both sides by ST

$\frac{ST}{ST}$ = ( $\frac{3}{5}$ ) ST / ST + $\frac{1.5S}{ST}$

1 = $\frac{3}{5}$ + $\frac{1.5}{T}$

1 - $\frac{3}{5}$ = $\frac{1.5}{T}$

$\frac{2}{5}$ =  $\frac{1.5}{T}$

T =  $\frac{1.5}{2 / 5}$

= 1.5 * ( 5/2  )

T = 3 . 75 hours

Hence,

His usual time to reach the destination is 3.75 hours