"> Question 9 & 10 | Job Exam Rare Mathematics (JEMrare)

Question 9 & 10

Question 9: A train 260 m long is running at speed of 45 km/hr. In what time will it pass a bridge 140 m long?

FPSC Assistant Director IB 2017



Solution:

This train will completely cross the bridge after covering distance equal to its length + length of bridge,’

Here distance  = Lenght of train + Length of bridge = 360+140= 400m

Speed V = 45 km/h= 45 X 1000 m/3600 sec= 12.5 m/sec

So,  we have.

S= 400m

v= 12.5m/s

t=?

Using formula;

S=vt

\Rightarrow t=\frac{S}{v}

\Rightarrow t=\frac{400}{12.5}

\Rightarrow t=32 sec

So the train will cross the bridge in 32 seconds

 

Question 10: What is the smallest natural number and prime number?

FPSC Assistant Director IB 2017

Solution:

Natural Numbers:

Set of natural numbers is;

N = \left \{ 1,2,3,4,5,......................... \right \}

So, here we can see smallest natural number is 1.

Prime Number :

Prime numbers are those numbers which are divisible by themselves or by 1 — only

P= \left \{ 1,2,3,5,7,11......................... \right \}

Here we can see smallest odd prime number is 1, and smallest and the only even prime number is 2.

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