A man drive his car to the office at 20miles/hr.
After reaching office, he realize that its a new year holiday so he went back home at a speed of 30miles/hr.
Discounting the time spent in the stoppage what was his average speed of his journey ? Select
A) 23miles
B) 25miles
C) 22miles
D) 24miles
E) 26miles
24miles   24miles/hr (not 25miles/hr which might be guessed by many)   24miles : distance traveled   T1 : time of going to office   T2 : time of returning back   Y : Average Speed   24miles = 20 * T1   T1 = 24miles/20   24miles = 30 * T2   T2 = 24miles/30   224miles = Y(T2 + T1)   224miles = Y(24miles/20 + 24miles/30)   224miles = Y(324miles/60 + 224miles/60)   224miles = Y(524miles/60)   Y = 12024miles/524miles   =&gt; Y = 24
<result>D</result>
A man drive his car to the office at 20miles/hr.
After reaching office, he realize that its a new year holiday so he went back home at a speed of 30miles/hr.
Discounting the time spent in the stoppage what was his average speed of his journey ?