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While traveling to the office, Dolly drives her car at a speed of 60 20 Mar 2025, 01:35
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While traveling to the office, Dolly drives her car at a speed of 60 kmph and then suddenly the car stopped on half of her distance to the office, so she travels half of the remaining distance by bus at 30kmph and the rest by walking at 10kmph. Find the average speed of Dolly?

A. 50 kmph

B. 40 kmph

C. \(33 \frac{1}{3}\) kmph

D. 24 kmph

E. 30 kmph


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D
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While traveling to the office, Dolly drives her car at a speed of 60 20 Mar 2025, 01:43
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Bunuel
While traveling to the office, Dolly drives her car at a speed of 60 kmph and then suddenly the car stopped on half of her distance to the office, so she travels half of the remaining distance by bus at 30kmph and the rest by walking at 10kmph. Find the average speed of Dolly?

A. 50 kmph

B. 40 kmph

C. \(33 \frac{1}{3}\) kmph

D. 24 kmph

E. 30 kmph

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Let Distance between her home and office = 4D
so she drives 2D 60
so she travels D 30
so she travels D 10

Average Speed = Total Distance / Total Time

Average Speed = 4D / [(2D/60)+(D/30)+(D/10)] = 4D*60 / 10D = 24
Answer: Option D

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While traveling to the office, Dolly drives her car at a speed of 60 20 Mar 2025, 08:18
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Total Distance= x

x/2 60 km/hr, time taken = x/120
x/4 30 km/hr, time taken= x/120
x/4 10 km/hr, time taken =x/40=3x/120

Avg speed = total distance /Total time = x/5x/120 = 24km/hr
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While traveling to the office, Dolly drives her car at a speed of 60 20 Mar 2025, 08:43
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Let total distance to office= 4d
........Distance....Speed....Time
CAR..... 2d ...... 60 kmph ...(2d/60)h
Bus...... d ...... 30 kmph ... (d/30)h
Walk..... d ...... 10 kmph ... (d/10)h
Total.... 4d ......Avg Speed ... (5d/30)h

Average Speed= Total distance/ Total time = 4d/(5d/30) = 24 kmph

Answer: D
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While traveling to the office, Dolly drives her car at a speed of 60 20 Mar 2025, 12:06
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Bunuel
While traveling to the office, Dolly drives her car at a speed of 60 kmph and then suddenly the car stopped on half of her distance to the office, so she travels half of the remaining distance by bus at 30kmph and the rest by walking at 10kmph. Find the average speed of Dolly?

A. 50 kmph

B. 40 kmph

C. \(33 \frac{1}{3}\) kmph

D. 24 kmph

E. 30 kmph


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Based on the fraction distance mentioned, let’s assume the total distance to be 4D.

Mode 1 : car - distance 2d - speed 60 kmph

Mode 2: bus - after stopping at half the total distance and travels for half of the remaining distance (2d)= d and speed = 30 kmph.

Mode 3 : walk - distance d - speed 10 kmph.

Average speed = Total distance / total time
= 4d / [ (2d/60) + (d/30)+ (d/10) ]
= 24 kmph option D
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While traveling to the office, Dolly drives her car at a speed of 60 20 Mar 2025, 23:30
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123Total
D2DDD4D
T2D/60D/30D/102D/60 + D/30 + D/10
V603010Avg speed = ?

Avg. speed = Total distance / Total time = 4D / ( 2D/60 + D/30 + D/10) = 4D/ (5D/30) = 4D*30/5D = 24

Answer: (D) 24 kmph
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While traveling to the office, Dolly drives her car at a speed of 60 27 Mar 2025, 01:07
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Let D = 120km
Dolly travelled 120/2 = 60km at 60kmph. So T = 1
Dolly travelled 60/2 = 30km at 30kmph. So T = 1
Dolly travelled 60/2 = 30km at 10kmph. So T = 3

Avg Speed = 120/(1+1+3) = 24

Bunuel
While traveling to the office, Dolly drives her car at a speed of 60 kmph and then suddenly the car stopped on half of her distance to the office, so she travels half of the remaining distance by bus at 30kmph and the rest by walking at 10kmph. Find the average speed of Dolly?

A. 50 kmph

B. 40 kmph

C. \(33 \frac{1}{3}\) kmph

D. 24 kmph

E. 30 kmph


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