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### Mathmetics

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

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##### The ratio between A's and Bs salary was 3:4,two year ago . The ratio's of individual salaries of A and B two year's ago and this year's salaries are 4:5 and 2:3 respectively. At present the total of their salary is Rs.4290. What is present salary of A ?
 1) Rs.1560 2) Rs.1600 3) Rs.1650 4) Rs.1840 5) None of these
Explanation :
Let, two year ago ,the ratio of between A'and B's salary was 3x: 4x respectively.

The ratio of their individual salary between two years ago and this year is 4y:5y and  2z:3z respectively.
So, 4y = 3x (A's last year salary)
or y = .75x   and  2z = 4x (B's last year salary)
or z = 2x
Now, the total of their salary is Rs.4290 .
So, 5y + 3z = Rs.4290
Replace y with .75x; replace z with 2x
So, 5(.75x) + 3(2x) = 4290
or 3.75x + 6x = Rs.4290    or 9.75x = 4290
or x = 4290/9.75 = 440
Then, A's present salary 3.75 (440) = Rs.1650 View Answer
##### The ratio of the sum and the difference of two numbers is 3: 1. Then what is the ratio of these two numbers ?
 1) 3 : 2 2) 2 : 1 3) 3 : 1 4) 4 : 3 5) None of these
Explanation :
Let, the number be ‘x’ and ‘y’
So, (x+y)/(x-y) = 3/1
or x + y = 3x - 3y
or 2x = 4y
or x:y = 2:1 View Answer
##### Two numbers are such that their difference, their sum and their product are in the ratio 1:7:24 respectively. What is the product of the two numbers ?
 1) 12 2) 24 3) 36 4) 48 5) None of these View Answer
##### The income of A,B and C together is Rs.14500 and they spend  60%,65% and 70% of their income respectively. If their savings are in the ratio 14:21:15 . What is the income of  B ?
 1) Rs.4000 2) Rs.4800 3) Rs.5600 4) Rs.6000 5) None of these
Explanation : We know that, income - expenditure = saving
Let, their income are 100% individually.
So, A's saving = 100 - 60= 40% ; B's saving = 100 - 65= 35% ; C's saving = 100 - 70= 30%
But their saving ratio are 14:21:15.
Then, A's income , 40% = 14 or 100% =( 14/40) x 100 = 35
B's income , 35% = 21 or 100% =( 21/35) x 100 = 60
C's income , 30% = 15 or 100% =( 15/30) x 100 = 50
So, 35x + 60x + 50x = Rs.14500
or 145x = Rs.14500
or x = 100
Therefore income of B= 100x60 = Rs.6000. View Answer
##### A and B are two different alloys of gold and copper prepared by mixing metals in the proportion 7 : 2 and 7 : 11 respectively. If equal quantities of the alloys are melted to form a third alloys C, find the ratio of gold and copper in C ?
 1) 5 : 7 2) 3 : 7 3) 7 : 5 4) 7 : 8 5) None of these
Explanation :
You see in first alloy the ratio is 7:2 and in alloy is 7:11.
So, let total in first alloy is 9kg and total in second alloy is ,18kg.
To equalise both, we LCM of both i.e. should be 18 kg.
Now,gold 14 and copper 4 kg in first , gold 7 and copper 11kg in second alloy.
Now, mix gold to gold and copper to copper.
14+7=21
And  4+11=15
So. Ratio is 21:15=7:5 View Answer
##### 729 ml of a mixture contains milk and water in the ratio 7:2. How much more water is to be added to get a new mixture containing milk and water in the ratio of 7:3  ?
 1) 72 litres. 2) 81 litres 3) 121 litres 4) 144 litres 5) None of these View Answer
##### If two alloys contain zinc and copper in the ratio of 2 : 1 and 4 :1. In what ratio the two alloys should be added together to get as new alloy having zinc and copper in the ratio of  3:1 ?
 1) 3 : 5 2) 5 : 7 3) 5 : 3 4) 7 : 5 5) None of these View Answer
##### An amount of money is to be distributed among P, Q and R in the ratio 5 : 8 : 12, respectively.If the total share of Q and R is four times that of P, what is definitely P's share ?
 1) Rs. 4000 2) Rs. 4800 3) Rs. 5000 4) Can't be determined 5) None of these
Explanation : Let, the  amount of P, Q and R are 5x, 8x and 12x respectively.
So, 8x +12x = 4 (5x)
Or 20x = 20x
Hence,we can not find their numerical values. View Answer
##### A mixture contains alcohol and water in the ratio of 6:1. On adding 8 litres of water, the ratio of alcohol to water becomes 6:5. Find the quantity of water in the mixture.
 1) 1 litres 2) 2 litres 3) 3 litres 4) 4 litres 5) Non e of these View Answer  View Answer