Mathmetics
ISBT Mathmetics for all banking PO,Clerk,IBPS PO,Railway,SSC,IAS,OAS Exams
Q91. 

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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Q92. 

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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Q93. 

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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Q94. 

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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Q95. 

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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Q96. 

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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Q97. 

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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Q98. 

1)  184  2)  192 
3)  196  4)  212 
5)  None of these 
Answer : 192
Explanation :
Explanation :
(x + y)^{2} = (x  y)^{2} + 4xy
or x + y = 28, x  y = 4
or 4xy = (28)^{2}  (4)^{2}
or 4xy = (28 + 4) (28  4)
or xy = = 32 x 6 = 192
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Q99. 

1)  Rs.400  2)  Rs.500 
3)  Rs.600  4)  Rs.300 
5)  None of these 
Answer : Rs.300
Explanation :
Explanation :
Given, A + B + C = 1200
or A + B + 2C = 700 + 800 = 1500
or 1200  C + 2C = 1500
or C = 1500  1200 = 300
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Q100. 

1)  Rs.6500  2)  Rs. 7500 
3)  Rs.9000  4)  Rs.12000 
5)  None of these 
Answer : Rs. 7500
Explanation : Let, the man's income be Rs.x.
Explanation : Let, the man's income be Rs.x.
Expenditure on food = x/3 and expenditure on house rent = 2x/5
His saving = x  (x/3 + 2x/5) = 4x/15
So,4x/15 = 2000
or x =( 2000 X 15 ) /4 = 7500.
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