On a 20 mile course, Pat bicycled at an avg rate of 39 miles / h for the first 12 min and , without a break, ran the rest of the distance at an avg rat of 8 miles / h. How many minutes did Pat take to cover the entire course ?
A. 75
B. 105
C. 117
D. 150
E. 162
OA is C
Is there an easy way to solve this problem without a lot of calculation ?
20 mile course
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S = d/t
for the first 12 mins
39 = d/12
d = 39 * 12/60 (12/60 to convert mins to hours)
d  7.8 miles
So pat covered 7.8 miles in first 12 mins.
Remaining distance = 20 7.8 = 12.2
again s = d/t
8 = 12.2/t
t = 12.2/8
t = 1 hr 32 mins or 92 mins
so total time taken = 12 +92 = 104 ( approx)
B
Is there something I am missing? the OA is C
for the first 12 mins
39 = d/12
d = 39 * 12/60 (12/60 to convert mins to hours)
d  7.8 miles
So pat covered 7.8 miles in first 12 mins.
Remaining distance = 20 7.8 = 12.2
again s = d/t
8 = 12.2/t
t = 12.2/8
t = 1 hr 32 mins or 92 mins
so total time taken = 12 +92 = 104 ( approx)
B
Is there something I am missing? the OA is C
SACX

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Unless she took a break, I also think the answer is B.
quocbao wrote:On a 20 mile course, Pat bicycled at an avg rate of 39 miles / h for the first 12 min and , without a break, ran the rest of the distance at an avg rat of 8 miles / h. How many minutes did Pat take to cover the entire course ?
A. 75
B. 105
C. 117
D. 150
E. 162
OA is C
Is there an easy way to solve this problem without a lot of calculation ?
Ossa Elhadary, PhD, CISA, PMP
Math Specialist
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The answer is not B
The answer is C
The questions ask how much time did it take to cover the entire distance which is the 12 + 105 = 117 mins
You guys are forgetting to add the 12 mins covered at 39 mph
The answer is C
The questions ask how much time did it take to cover the entire distance which is the 12 + 105 = 117 mins
You guys are forgetting to add the 12 mins covered at 39 mph
Wht?!!!!hrishikesh05 wrote:The answer is not B
The answer is C
The questions ask how much time did it take to cover the entire distance which is the 12 + 105 = 117 mins
You guys are forgetting to add the 12 mins covered at 39 mph

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Sorry for late replying. OA is B. This was my mistake when I post the question.
What I want to ask in this question is that whether there is a way to finish the question easier ? Like plugging the number back to the question ? Will it be faster ?
What I want to ask in this question is that whether there is a way to finish the question easier ? Like plugging the number back to the question ? Will it be faster ?