Mental Ability

Friday, 25 March 2016

#21 Percentage Question

What percent of 7.2 kg is 18 gms ?

A) .25%
B) .5%
C) .75%
D) 1%

Answer: A) .25%

Explanation:

Required percentage = (18/7200 * 100)% = 1/4% = 0.25%

Wednesday, 23 March 2016

In a competitive examination in State A, 6% candidates got selected from the total appeared candidates. State B had an equal number of candidates appeared and 7% candidates got selected with 80 more candidates got selected than A. What was the number of candidates appeared from each State ?

A) 4000B) 8000C) 12000D) 16000

Answer: B) 8000

Explanation:

Let the number of candidates appeared from each state be x.

In state A, 6% candidates got selected from the total appeared candidates

In state B, 7% candidates got selected from the total appeared candidates

But in State B, 80 more candidates got selected than State A

From these, it is clear that 1% of the total appeared candidates in State B = 80

=> total appeared candidates in State B = 80 x 100 = 8000

=> total appeared candidates in State A = total appeared candidates in State B = 8000

#18 Percentage Question

The population of a town was 1,60,000 three years ago, If it increased by 3%, 2.5% and 5% respectively in the last three years, then the present population in

A) 155679
B) 167890
C) 179890
D) 177366

Answer: D) 177366

Explanation:

Present population = 160000 * (1 + 3/100)(1 + 5/200)(1 + 5/100)

= 177366.

#17 Percentage Question

if the price of a book is first decreased by 25% and then increased by 20%, then the net change in the price will be :

A) 10
B) 20
C) 30
D) 40

Answer & ExplanationAnswer: A) 10

Explanation:

Let the original price be Rs. 100.

New final price = 120 % of (75 % of Rs. 100) = Rs. (120/100 * 75/100 * 100) = Rs. 90.

Decrease = 10%

Sunday, 20 March 2016

#10 Time and Distance

Sujit runs at 6 km/hour and Rana at 8 km/hour .Rana catches Sujit in 9 minutes.What was the distance between sujit and Rana, when Rana started?

(a) 223 metres
(b) 153 metres
(c) 300 metres
(d) 350 metres.

Ans 9. 300 metres

Note : Try it. Practice question

#9 Time and Distance

Walking at 5/4th of his usual speed, Mr Subramaniam his office 10 minute early .Find hid usual reaching time.
(a) 20 min.
(b) 12 1/2 min.
(c) 40 min.
(d) 50 min.

Ans 8. 50 min.

Note : Try it. Practice question

#7 Time and Distance

Ashok left mathura at 5 a.m. An hour and a half later Brijesh left Mathura, his speed bring 5 kmph higher than that of Ashok. At 9:30 p.m. on the same day the distance between Ashok and Brijesh was 21 km.What is the speed of Ashok in kmph?

(a) 80 or 20
(b) 75 or 25
(c) 70 or 30
(d) 64 or 36

Ans 7. 64 or 36

Hint: Ashok travles for ( 12-5) + 9:30 hours till 9:30 p.m. Brijesh travels for (12-6:30) + 9:30 p.m.

There are two possibilities:

Ashok could be leading Brijesh or Brijesh could be leading Ashok.

#2 Time and Distance

A person covers a certain distance on a train. If the train moved 6 km/hour faster, it would take 40 minutes less. If it moved 3 km/hour slower , it would take 30 minutes more .Find the distance.

Ans 6.

#1 Time and Distance

Without stoppages, a train travels a certain distance with an average speed of 90 km/hour, and with stoppages it cover the same distance with an average speed of 60 km/hour. Find the stoppage time per hour of the train.

Ans 5.

#3 Time and Distance

Two trains are running at 40 km/hour and 20 km/hour respectively in the same direction . The faster train completely passes a man siting in slower train in 5 seconds. Find the length of faster train.

Ans 4.

#4 Time and Distance

Two trains 121 metres long and 99 metres long are running in opposite direction with speeds of 40km/hour and 32 km/hour respectively . In what time will they completely clear each other vfrom the moment they meet ?

Ans 3.

#6 Time and Distance

A train during its course of journey from station A to station B,travels for 2 hours at 30 km.hour, for 3 hours at 40 km/hour and for 5 hour at 50 km/hour, Find its average speed.

Ans 2.

#5 Time and Distance

A cyclist covers a certain journey at 50 km/hour and returns at a speed of 60 km/hour. Find his average speed.

Ans 1.

#8 Time and Distance

A railway passenger counts the telegraph posts in the railway track as he passes them. if they are 40 metres apart and the train is going at a speed of 24 km/hour how many will he pass per minute?

(a) 15
(b) 10
(c) 13
(d) 16

Ans 10. 10

Note : Try it. Practice question

Thursday, 17 March 2016

#14 Percentage Question

If 75% of a number is added to 75, then the result is the number itself. The number is :

A) 100
B) 200
C) 300
D) 400

Answer: C) 300

Explanation:

Let the number be x, Then

75% of x + 75 = x

x = 300 .

#15 Percentage Question

A student has to obtain 33% of the total marks to pass. He got 125 marks and failed by 40 marks. The maximum marks are :

A) 500B) 600C) 800D) 1000

Answer: A) 500

Explanation:

Given that the student got 125 marks and still he failed by 40 marks

=> The minimum pass mark = 125 + 40 = 165

Given that minimum pass mark = 33% of the total mark

#16 Percentage Question

If 75% of a number is added to 75, then the result is the number itself. The number is :

A) 100
B) 200
C) 300
D) 400

Answer: C) 300

Explanation:

Let the number be x, Then

75% of x + 75 = x

x = 300 .

#13 Percentage Question

The ratio 5 : 4 expressed as a percent equals :

A) 12.5 %
B) 40 %
C) 80 %
D) 125 %

Answer: D) 125 %

Explanation:

5 : 4 = 5/4 = ( (5/4) x 100 )% = 125%.

#12 Percentage Question

405 sweets were distributed equally among children in such a way that the number of sweets received by each child is 20% of the total number of children. How many sweets did each child recieve ?

A) 9B) 10C) 11D) 12

Answer: A) 9

Explanation:

Let the total number of children be x.

Then, x * (20% of x) = 405