M4maths Previous Puzzles

06 Aug 2020 Race

In a 10 km race. Sushant, Rajkumar, and Suraj, each running at uniform speed, get the gold, silver, and bronze medals, respectively. If Sushant beats Rajkumar by 1 km and Rajkumar beats Suraj by 1 km, then by how many metres does Sushant beat Suraj?

OPtion

1) 1.5 km
2) 1.6 km
3) 1.8 km
4) 1.9 m
5) 2.0 km
6) 2.1 km
7) 1900 km
8) 1800 m
9) 1900 m
10) None of these

Solution

Sushant : Rajkumar = 10 : 9
Rajkumar : Suraj = 10 : 9
⇒ The ratio of speeds of Sushant : Rajkumar : Suraj = 100 : 90 : 81
In the same time that Sushant travels 100 m, Suraj travels 81 metres ⇒ In the same time that Sushant travels 10000 m, Suraj would travel 8100 m
or Sushant would beat Suraj by 1900 m.

Correct Option: 9 Best Solution (5)

G.S.Kantharao   4 years AGO

Susant:Raj Kumar=10:9
Raj Kumar :Suraj=10:9
Susan:Raj Kumar:Suraj=100:90:81
Hence Sidang beats Suraj by 1.9 km.
My option is 9✍️

Like? Yes (1) | No   

Varun   4 years AGO

Sushant 10 = Raj 9
Raj 10 = Suraj 9
Sushant 10,000 = Raj 9000
Raj 9000 = Suraj 8100
= 10,000-8100 = Option (9)

Like? Yes (1) | No   

SAYAN CHATTERJEE   4 years AGO

let, thd speed of Sushant, Rajkumar and Suraj be S, R and Su
so, 10/S= 9/R
10/R= 9/Su
so, 100Su= 81S
now, Sushant travels, 10/S time
so, during that time, Suraj travels
10/S*Su
= 10/S*81/100
= 8.1 km
so, Sushant beats him by (10-8.1)= 1.9 km
Option 9.

Like? Yes | No   

M4 Murali   4 years AGO

1)Sushanth beats Rajkumar by 1km
Means when rajkumar travels 9km suraj traveks 10km
means when rajkumar traavels 0.9km suraj travels 1km
1km(Sus)------>0.9km(Raj)
2)Similary 1km(Raj)---->0.9km(Sur)
3)from 1 and 2
1km(Sus)---->(0.9*0.9)=0.81km(Sur)
so when sushanth travels 10km suraj travels 8.1km where he beats him by 1.9km

Like? Yes | No   

RAMADURAI NATESAN   4 years AGO

When sushant completes 10 km, raj would be at 9 km.
When raj completes 10 km, suraj will be at a point
( 9/10 ) * 9 = 8.1 km. This means sushant beats raj by
10.00 - 8.10=1.9 km =10km = 1900 metres

Like? Yes | No