Mathmetics
ISBT Mathmetics for all banking PO,Clerk,IBPS PO,Railway,SSC,IAS,OAS Exams
Q61. 

1)  Rs.820  2)  Rs.890 
3)  Rs.1020  4)  Rs.1250 
5)  None of these 
Answer : Rs.890
Explanation :
Explanation :
A : B : C = (8,000 x 6) : (4,000 x 8) : (8,000 x 8) = 48 : 32 : 64 = 3 : 2 : 4.
B's share = ( Rs. 4005/9) x 2 = Rs. 890.
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Q62. 

1)  Rs.1200  2)  Rs.1250 
3)  Rs.1450  4)  Rs.1500 
5)  None of these 
Answer : Rs.1500
Explanation :
Explanation :
Let, the total profit be Rs. 100.
After paying to charity, A's share = (Rs. 95 /5)x 3 = Rs. 57.
If A's share is Rs. 57, total profit = Rs. 100.
If A's share Rs. 855, total profit = ( 855/57) x100 = 1500
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Q63. 

1)  4 : 5  2)  5 : 4 
3)  3 : 2  4)  Data Inadequate 
5)  None of these 
Answer : 5 : 4
Explanation :
Explanation :
C.P. = S.P.  Profit
or C.P. = 5 1 = 4
or S.P. : C.P. = 5 : 4
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Q64. 

1)  Rs. 4,250  2)  Rs. 4,500 
3)  Rs. 6,400  4)  Rs. 7200 
5)  None of these 
Answer : Rs. 7200
Explanation :
Explanation :
We know that Sum = (S.I X 100 )/ R X T
= (Diff. in S.I X 100 ) / Diff. in rate X Time
= (72 X100)/ 2 X 5 = Rs. 7200.
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Q65. 

1)  5: 17  2)  1:11 
3)  11:1  4)  2:3 
5)  None of these 
Answer : 11:1
Explanation :
Explanation :
By alligation method :
2.40 3.60
2.50
3.60  2.50 2.50  2.40
= 1.10 10
So, Ratio will be 11 : 1.
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Q66. 

1)  2  2)  4 
3)  6  4)  8 
5)  None of these 
Answer : 6
Explanation :
Explanation :
Let,speed of boat man be x kmph.
So, speed in down stream =(x+2) kmph. and speed in upstream = (x2) kmph.
Since, distance is constant for both case ,
the equation = 2(x2) = (x+2)
or 2x4 = x+2
or x= 6 kmph
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Q67. 

1)  456 km  2)  482 km 
3)  548 km  4)  552 km 
5)  None of these 
Answer : 552 km
Explanation :
Explanation :
Given, the first term, a = 35, common difference, d = 2 and total number of terms, (n) = 12.
The sum of this series will be the total distance travelled.
Sum, S_{n}= n/2[2a + (n  1) d] = 6 [70 + 11 x 2] = 552 km.
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Q68. 

1)  3  2)  5 
3)  9  4)  11 
5)  None of these 
Answer : 11
Explanation :
Explanation :
Let, the ten's digit be x and unit's digit be y.
Then, number = 10x + y.
Number obtained by interchanging the digits = 10y + x.
(10x + y) + (10y + x) = 11(x + y), which is divisible by 11.
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Q69. 

1)  Rs.800  2)  Rs.840 
3)  Rs. 880  4)  Rs.900 
5)  None of these 
Answer : Rs.900
Explanation :
Explanation :
Let, the price of the pen be ‘x’ and that of a pencil be ‘y’.
16x + 12y = 720 or (16x) X 5/4 + 12y X 5/4 = 720 X 5/4
or 20x + 15y = 900
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Q70. 

1)  3 : 2  2)  2 : 1 
3)  3 : 1  4)  4 : 3 
5)  None of these 
Answer : 2 : 1
Explanation :
Explanation :
Let, the number be ‘x’ and ‘y’
So, (x+y)/(xy) = 3/1
or x + y = 3x  3y
or 2x = 4y
or x:y = 2:1
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