IBPS SO Prelims Exam Model Paper 10

Given:
The person walks

4

5

of his usual speed.
He was a 20-minute delay.
Formula used:
Distance = Speed × Time
Calculation:Let the distance be D and his speed be S
So, his usual time to reach the office =

D

S

Now, his new speed =(

4

5

)S
According to the question,
{

D

( 4 5 )

S}−(

D

S

)=20 minutes
(5

D

4

S)−(

D

S

)=(

20

60

) hours
(

D

4

S)=

1

3

hours
(

D

S

)=

4

3

hours
{(

4

3

)‌times‌60} minutes =80 minutes
∴ His original time to reach the office is 80 minutes.