# Speed Time & Distance Quiz For Upcoming Exams Answers

Q1. Option C

Differences in Time taken for both movements are same here. So,

Speed = 2* (increased speed)*(decreased speed) /difference in speed

= 2*8*4 /8- 4

= 2*8*4/4

= 16kmph

Q2. Option D

Difference in time taken =40-30= 10min = 10/60 = 1/6 hr

Speed during the next journey= 15+3 =18kmph

So time taken, x/15 –x/18 = 1/6

3x/ (15*18) =1/6

X / (5*18) = 1/6

x = (18*5)/6

Distance (X) = 15km

Q3 Option C

Let assume the usual speed of the train X kmph

Then, 75% of usual speed = 75*x/100 =3x/4

Now, L /x = 12

L = 12x

Again, (L+450) /(3x/4) =18

12x+450 = 18*(3x/4)

450+ 12x = 27x/2

450+12x = 13.5x

1.5x = 450

X = 450/1.5 =675m

Speed = 18*(5/18) = 5m/s;

Time taken = Distance /Speed = 675/5= 135 Seconds

=> 135/60 min = 2 hr 15 min

Q4. Option B

Q5 Option C

Speed of first train= x/4 km/h

Speed of second train =x/3 km/h

Let they meet y hrs after 7.00am

Then, according to the question,

X/4 *y +x/3 * (y-2) =X

Y/4 +(y-2)/3 =1

3y+4(y-2) =12

3y+4y-8 =12

7y=20

Y=20/7

Y =2 hrs 51 min 25 sec

Two trains cross each other = 7+2.51 = 9.51 am(approx)

Q6 Option A

Let the length of train B be X m.

Then, length train A =2X/5

Now the speed of train B to that of train A = (X/70): (2X/5 /45)

= (70/x) *(2x/225)

= 140: 225 = 28:45

Q7 Option C
Speed of the truck= D/T = 294/7 = 42km/hr

Now, Speed of car = (Speed of truck +14) km/hr = 42+14 = 56km/hr

Distance of car = 294+16 = 310 km

Time Taken = 310/56 = 5hr 32 min

Q8 Option B

Relative speed = (65.5 /35) *60 = 786/7 kmph

Speed of A = 786/7 -45 = 471/7 = 67.28 kmph

Q9 Option B

D=78km; a=16kmph, b=10kmph

According to the formula,

Distance travelled by

R = AC =2D*(a/a+b)

= 2*78 *(16/ (10+16))

= 2*78 *(16/26)

= 2*78*(8/13) =96km

Q10 Option C
Express:

Time taken to cover 75km (including stoppage) = 30min+6min =36min

Time taken to cover the total distance by Express= (36/75*825) +36min = 432min

Local Train:

Time taken to cover 37.5km (including stoppage) = 30min+2min =32min

In 32min, distance covered =37.5km

Required total distance = 432*(37.5/32)= 506.25km