Here in this blog we are discussing about some basic aptitude questions with easier examples .

1.The angle of elevation of a ladder leaning against a wall is 60 o and the foot of the ladder was 4.6 m away from the wall. Find the length of the ladder.

SOLUTION :

A    ( AB = wall , AC = ladder and BC =distance between them )

B   C

Angle of elevation = 60o

Distance between the ladder and the wall = BC = 4.6 m

Length of the ladder = AC = ?

Cos 60 o = Adjacent side / Hypotenuse  = BC /AC

1/2 = 4.6 / x    =>   x = 4.6 * 2 = 9.2 m

Hence the length of the ladder = 9.2 m.

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2.Class A has higher enrollment than Class B

Class C has lower enrollment than Class B

Class A has lower enrollment than Class C

If the first two statements are true then the third statement is UNCERTAIN.

REASON :    Class A > Class B  by statement i)

Class C < Class B  by statement ii)

• Class A > Class B > Class C
• so Class A can’t be less than Class C

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3.A train of 240 m long crosses a pole in 24 seconds then how long it will take to cross the platform of 650 m long.

SOLUTION :

Distance  = 240 m

Time taken = 24 seconds

Speed =  Distance / Time taken

= 240 / 24         =   10 m/sec

Now total distance = 240 + 650 = 890 m

Time taken =     Distance / Speed

=   890  /   10       =  89   seconds

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4. On selling 17 balls at the cost of Rs.720 , there is a loss equal to the cost price of 5 balls. What is the cost price of each ball ?

SOLUTION :

Selling price of 17 balls = Rs. 720

Loss % = Loss * 100 / Cost price

Cost price =      100 * Selling price

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100 – loss %

=           100 * 720

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100 –  5*100 / 1700

=           100 * 720 * 1700                              100 * 720 * 1700

———————————     =           ————————–

1700 – 500                                                      1200

= Rs. 1020          =>  C.P of one ball = 1020 /17 =  Rs.60

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5. A goods train runs at the speed of 72 kmph and crosses a

250 m long platform in 26 seconds. What is the length of the goods train ?

SOLUTION :

Length of the train = x meters.

Speed = 72 kmph = 72 * ( 5 / 18 ) m / sec

=  20 m /sec

Total distance covered = x + 250 m

Time taken to cover the distance of ( x + 250 ) m = 26 seconds

• Speed = x + 250  / 26
• 20 = x  + 250 /  26
• 20 * 26 = x + 250
• 520 m = x + 250
• X = 520 – 250 = 270 m

Hence the length of the goods train = 270 m

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