Mathmetics
ISBT Mathmetics for all banking PO,Clerk,IBPS PO,Railway,SSC,IAS,OAS Exams
Q1. 

1)  Rs.8000  2)  Rs.10,000 
3)  Rs.12,000  4)  Data Inadequate 
5)  None of these 
Answer : Rs.8000
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Q2.  A person invested a total amount of Rs 15 lakh. A part of it was invested in a fixed deposit earning 6% annual interest, and the remaining amount was invested in two other deposits in the ratio 2 : 1, earning annual interest at the rates of 4% and 3%, respectively. If the total annual interest income is Rs 76000 then what was the amount (in Rs lakh) invested in the fixed deposit ? 
1)  Rs. 6 Lakhs  2)  Rs. 7 Lakhs 
3)  Rs. 8 Lakhs  4)  Rs. 9 Lakhs 
5)  None of these 
Answer : Rs. 9 Lakhs
Explanation :
Explanation :
Let Rs x be invested in FD.
So, Remaining amount = Rs. 15 Lakhs  x, which is invested in the ratio 2 : 1
So, each investment would have 1/3(15x) and 2/3(15x) investments respectively
So, Total annual interest income = 6% of x + 4% of 1/3(15x) + 3% of 2/3(15x) = 76000
Rewriting Rs.76000 as Rs. 0.76 Lakhs,
6% of x + 4% of 1/3(15x) + 3% of 2/3(15x) = 0.76
Multiply both sides by 100,
6x + 4/3(15x) + 2(15x) = 76
6x +11/3 (15x) = 76
165 + 18x 11x = 228
7x = 63
x = 9 (or) Rs. 9 Lakhs
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Q3. 

1)  Rs.6400  2)  Rs.6500 
3)  Rs.7200  4)  Rs.7500 
5)  None of these 
Answer : Rs.6400
Explanation :
Explanation :
Explanation:
Let the sum invested in Scheme A be Rs. x and that in Scheme B be Rs. (13900  x).
Then, (x x 14 x 2)/100 + ((13900  x) x 11 x 2) /100= 3508
28x  22x = 350800  (13900 x 22)
or 6x = 45000
or x = 7500.
So, sum invested in Scheme B = Rs. (13900  7500) = Rs. 6400.
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Q4.  A person invested some amount at the rate of 12% simple interest and a certain amount at the rate of 10% simple interest. He received yearly interest of Rs. 130. But if he had interchanged the amounts invested, he would have received Rs.4 more as interest. How much did he invest at 12% simple interest ? 
1)  Rs.400  2)  Rs.500 
3)  Rs.700  4)  Rs.800 
5)  None of these 
Answer : Rs.700
Explanation :
Explanation :
Explanation :
Let the amount invested at 12% be x and the amount invested at 10% be y respectively
( x x 12 x 1)/100 +( y x 10 x 1)/100 = 130
1.2x + y = 1300
Similarly, 1.2y + x = 1340
or (1.2x) x 1.2 + 1.2y = 1300 x 1.2
x +1.2y = 1340
or 0.44x = 1560  1340 = 220
or x = (220/0.44)  Rs. 500
or y = 1300  1.2 x 500 = Rs. 700
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Q5.  A person invested some amount at the rate of 12% simple interest and a certain amount at the rate of 10% simple interest. He received yearly interest of Rs. 130. But if he had interchanged the amounts invested, he would have received Rs.4 more as interest. How much did he invest at 12% simple interest ? 
1)  Rs.400  2)  Rs.500 
3)  Rs.700  4)  Rs.800 
5)  None of these 
Answer : Rs.700
Explanation :
Explanation :
Explanation :
Let the amount invested at 12% be x and the amount invested at 10% be y respectively
( x x 12 x 1)/100 +( y x 10 x 1)/100 = 130
1.2x + y = 1300
Similarly, 1.2y + x = 1340
or (1.2x) x 1.2 + 1.2y = 1300 x 1.2
x +1.2y = 1340
or 0.44x = 1560  1340 = 220
or x = (220/0.44)  Rs. 500
or y = 1300  1.2 x 500 = Rs. 700
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Q6.  A person divide his capital worth Rs.4332 into three parts in such way their interest after 2,3 and 4 years equal to each other. The rate of interest on these three parts have to be 4% , 7% and 11% per annum, respectively at S.I. What is the difference between the largest and the smallest part of money invested ? 
1)  Rs.1860  2)  Rs.2052 
3)  Rs.2268  4)  Rs.2468 
5)  None of these 
Answer : Rs.2268
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Q7. 

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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Q8. 
1)  Rs.4000  2)  Rs.5000 
3)  Rs.6000  4)  Rs.7000 
5)  None of these 
Answer : Rs.5000
Explanation : Let, the sum lent at 12% simple interest is Rs.X.
Explanation : Let, the sum lent at 12% simple interest is Rs.X.
So, the sum lent at 15% simple interest is (Rs.12000  x).
Then,
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Q9. 

1)  Rs. 12380  2)  Rs.16176 
3)  Rs.18240  4)  Rs.19020 
5)  None of these 
Answer : Rs.16176
Explanation : SI = [(67400 x 3 x 8) ] /100 = Rs.16176
Explanation : SI = [(67400 x 3 x 8) ] /100 = Rs.16176
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Q10.  A person deposited Rs.8000 which amounted to Rs.9200 after 3 years at simple interest . Had the interest been 2% more, how much he would get ? 
1)  Rs.8,660  2)  Rs.9,680 
3)  Rs.10,620  4)  Rs.11,540 
5)  None of these 
Answer : Rs.9,680
Explanation : Given, P = 8,000 , T=3 yrs A= 9200
Explanation : Given, P = 8,000 , T=3 yrs A= 9200
So, S.I = 9200  8000 = 1200
Then , R = (1200 X 100 ) / 8000 X 3 = 5%
After 2% rate increases , new rate will be 7%.
So, new SI=( 8000 X 3 X 7) / 100 = 1680
Thus, new amount = 8000 + 1680 = 9,680
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