Amdocs time speed and distance Quiz-1

New speed = 6/7 of usual speed. New time = 7/6 of usual time ∴ [7/6 of usual time] – (usual time) = 1/5 hr. ⇒ 1/6 of usual time = 1/5 hr ⇒ usual time = 6/5 hr = 1 hr 12 min.

Speed of boat =x
speed of current = y
distance = d
x-y=5d /44 ( d / time)
x+y= d/4
from both equations
x/y =8/3
so ratio can be 8:3

A:B = 100 : 75
b : C = 100 : 96
a :C = a/b×b/c = 100/75×75/96 = 100/72 = 100:72
A beats C by 100-72 m= 28 m

Let there be 1 kg cake.

1 kg = 1000 g

Father ate 1/5th of the cake.

⇒ 1000*1/5

= 200 g

So, father ate 200 g of cake.

Remaining quantity of cake = 1000 - 200 = 800 g

Let the number of members in the family excluding father be x

Father had 4 times as much as others had. So, each family member will get = 200/4

Therefore, number of family members = x*(200/4) = 800

⇒ 200x = 800*4

⇒ 200x = 3200

⇒ x = 3200/200

⇒ x = 16

Total members in the family = 16 + 1 father

= 17 members

Hence, there are 17 members in the family.

Let the initial expenses on Sugar was Rs. 100.
Now, Price of Sugar rises 25%. So, to buy same amount of Sugar, they need to expense,
= (100 + 25% of 100) = Rs. 125.
But, They want to keep expenses on Sugar, so they have to cut Rs. 25 in the expenses to keep it to Rs. 100.
Now, % decrease in Consumption,
(25/125)*100 = 20%.

Mind Calculation Method;

100-----25%↑---→125------X%↓---→100.

Here, X = (25/125)*100 = 20%.

Let the total distance covered be S km.
Total time taken=
S
(2×40)
+
S
(2×60)
=
5S
240
hr
Average speed =S×
240
5S

= 48 km/hr

Let the speed of the cyclist be x km/h and wind be y km/h
1
(x+y)
=
3
60

⇒ x+y=20 -------- (i)

And,
1
(x−y)
=
4
60

⇒ x−y=15 -------- (ii)

On solving both the equations we get:
x=
35
2
,y=
5
2

Now, time taken by cyclist without wind:
=
2
35
×60=
24/7min

Let the speed of the stream be x km/hr. Then,

Speed downstream = (15 + x) km/hr,

Speed upstream = (15 - x) km/hr.

30/(15 + x) + 30/ (15 - x) = 4 1/2
900/(225 - x²) = 9/2
9x² = 225

x² = 25

x = 5 km/hr.

Let the speed of goods train be x km/hr.
Then, (50+x)×(
5
18
)=
187.5
9

⇒ x= 25 km/hr

T = (121 + 165)/ (80 + 65) * 18/5

T = 7.15