M4maths Previous Puzzles

25 Oct 2017 Marbles

I have a certain number of marbles to divide equally among 24 boys. When total number of marbles's are increased by 9 and number of boys are increased by 3 then each boy receives 4 marbles less when compared to earlier. How many marbles did I had initially?

OPtion

1) 882
2) 984
3) 930
4) 960
5) 930
6) 936
7) 876
8) 920
9) 890
10) None of these

Solution

Case-1
No of boys = 24
No. of Marbles = x
No. of marbles each boy gets = x/24 ----(i)

Case-2
Increased no. of boys = 27
Increased no. of marbles = x+9
No. of marbles each boy gets after increasing by 9 = (x+9)/27 ----(ii)

As per question boys receive 4 less marbles in case-2 when compared to case-1
So No. of marbles each boy gets after increasing by 9 = (x/24) - 4 ----(iii)

Equating (ii) and (iii)
(x+9)/27 = (x/24) - 4
(x+9)/27 = (x - 96)/24
= 24x + 216 = 27x - 2592
=> 3x = 2808
=> x = 936 Option 6)

So in case-1 you should distribute = 936/24 = 39 marbles
and in case-2 you should distribute = 945/27 = 35 marbles

Correct Option: 6 Best Solution (0)

24 Oct 2017 Age

A is 8 years older than B who is three times as old as C. The total of the ages of A, B and C is 29 years. What is the average of A and B ages?

OPtion

1) 10 years
2) 10.5 years
3) 11 years
4) 11.5
5) 13 years
6) 12 years
7) 12.5 years
8) 13.5 years
9) 9 years
10)None of these

Solution

Let’s assume Age of B be B years
Age of A = B+8
Age of C = B/3

Total age = B + 8 + B + B/3 = 29
Solving 7B/3 = 21
B = 9
C = B/3 = 9/3 = 3 years
A = 9+8 = 17 years
Average = (17+9)/2 = 26/2 = 13 years

Option 5)

Correct Option: 5 Best Solution (0)

23 Oct 2017 Speed and Time

A boatman goes 3 km against the current of the stream in 1 hour and goes 3 kms along the current in 30 minutes. How long will it take to go 6 km in stationary water?

OPtion

1) 1 hours 33 minutes
2) 1.23 hours
3) 1 hours 43 minutes
4) 1 Hours
5) 1 hours 15 minutes
6) 1.03 hours
7) 1 hours 20 minutes
8) 1 hours 25 minutes
9) 1.5 hours
10)None of these

Solution

Speed (upstream) =3/1 km/hr
Speed (downstream)= 3/0.5= 6 km/hr

Speed in still water = 1/2 (6+3) = 4.5 km/hr

Time taken in stationary water to go 6 KM = 6/4.5 = 1.333333 hr = 1 Hour 20 minutes

Option 7)

Correct Option: 7 Best Solution (5)

20 Oct 2017 Age

"A father said to his son, ""I was as old as you are at the present at the time of your birth"". If the father's age is
64 years now, what was the son's age fifteen years back?"

OPtion

1) 21
2) 20
3) 19
4) 18
5) 22
6) 16
7) 17
8) 23
9) 24
10) None of these

Solution

Let the sons current age be x
So fathers age x years back when son was born => 54-x = x
Solving we get x = 32
15 Years back son's age = 32-15 = 17 years

Correct Option: 7 Best Solution (9)

19 Oct 2017 CODE DECODE

If RAMAYANA is coded as 3302208000 then what is the code of MAHABHARAT

OPtion

1) 2173716352000
2) 2173726352000
3) 2173736352000
4) 2173794352000
5) 2173795352000
6) 2173776352000
7) 2173797352000
8) 2173796352000
9) 2173799352000
10) None of these

Solution

Each alphabet is coded as
A=1, B=2, C=3 ...Z=26
Code of a given word is obtained by sum of (Each alphabet code multiplied with its position in the given word.)

For example in RAMAYANA code of R is 18 and its position value is 1
Code of A is 1 and its position value is 2
Similarly code of M is 13 and its position value is 3
So RAMAYANA code is obtained as 1*18 + 2*1 + 3*13 + 4*1 + 5*25 + 6*1 + 7*14 + 8*1 = 3302208000

Similarly for MAHABHARAT the code obtained is:
13*1)*(1*2)*(8*3)*(1*4)*(2*5)*(8*6)*(1*7)*(18*8)*(1*9)*(20*10)= 2173796352000

Correct Option: 8 Best Solution (2)

18 Oct 2017 CI & SI

The difference between simple interest and the compound interest on a certain amount of money for 3 years at 5.0% per annum is Rs. 183. The sum is:

OPtion

1) Rs.22000
2) Rs.26000
3) Rs.23000
4) Rs.24090
5) Rs.25000
6) Rs.27000
7) Rs.21000
8) Rs.28000
9) Rs.20000
10)None of these

Solution

Let the sum be Rs.x. then S.I.=(x*5*3 / 100) = 3x/20 = 0.15x
C.I = [x(1+5/100)^3 -x] = [x(9261/8000) -x] = 0.157625x
CI-SI=183
=> 0.157625 - 0.15x = 183
=> 0.007625x = 183
=> x = 24000

Option 10)

Correct Option: 10 Best Solution (0)

17 Oct 2017 Mixture

A merchant has 62 kg of sugar, part of which he sells at 8% loss and the rest at 8% profit. He gains 4% on the whole. What is the difference between the quantities of sugar sold at 8% profit and that sold at 8% loss?

OPtion

1) 30 kg
2) 15.5 kg
3) 46.5 kg
4) 32 kg
5) 31 kg
6) 40 kg
7) 35 kg
8) 36 kg
9) 14 kg
10)None of these

Solution

(Quantity of Cheaper)/(Quantity of Dearer) = (Price of Dearer - Mean Price)/(Mean Price - Price of Cheaper)

(Quantity of Cheaper)/(Quantity of Dearer) = (108 - 104)/(104-92) = 4/12 = 1/3

Total Quantity = 62 KG

The quantity sold at 8% loss is = (1/4) * 62 = 15.5 Kgs
The quantity sold at 8% profit is = (3/4) * 62 = 46.5 Kgs
Difference between Quantity = 46.5 - 15.5 = 31 Kgs

Option 5)

Correct Option: 5 Best Solution (0)

16 Oct 2017 Stocks & Shares

The market value of a 8.5% stock, in which an income of Rs. 380 is derived by investing Rs. 9500, brokerage being 1/4 %, is:

OPtion

1) 212.25
2) 212.75
3) 213.00
4) 212.50
5) 213.50
6) 211.75
7) 211.50
8) 211.25
9) 213.25
10) None of these

Solution

For an income of Rs. 380, investment = Rs. 9500

For an income of Rs. 8.5, investment = Rs. (9500/380) * 8.5 = 212.5
For a Rs. 100 stock, investment = Rs. 212.5

Market value of Rs. 100 stock = Rs. 212.5 - 0.25 = Rs. 212.25

Correct Option: 1 Best Solution (0)

13 Oct 2017 Discount

The marked price of a dress is Rs.4000. A shopkeeper offers 15% discount on this shirt and then again offers 10% discount on the new price, and then and then again offers 5% discount on the new price . How much will you have to pay, finally?

OPtion

1) 2700
2) 2760
3) 2970
4) 2917
5) 2901
6) 2907
7) 2709
8) 2967
9) 2696
10) None of these

Solution

Price after 1st Discount = 4000*85/100 = 3400
Price after 2nd Discount = 3400*90/100 = 3060
Price after 3rd discount = 3060*95/100 = 2907

Hence Option 6)

Correct Option: 6 Best Solution (15)

12 Oct 2017 Age

"A father said to his son, ""I was as old as you are at the present at the time of your birth"". If the father's age is
48 years now, what was the son's age seventeen years back?"

OPtion

1) 10
2) 11
3) 9
4) 5
5) 8
6) 6
7) 0
8) 4
9) 7
10) None of these

Solution

Let the sons current age be x
So fathers age x years back when son was born => 48-x = x
Solving we get x = 24
17 Years back son's age = 24-17 = 7 years

Correct Option: 9 Best Solution (14)