Mathmetics

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

Previous123Next

Q1.
In a 96 litre mixture of water and milk, water is only 40%. The milkman sold 12 litres of the mixture to a customer and then added 10 litres of pure milk and 15 litres of water in the mixture. What is the approximate percentage of water in the final mixture?

1) 40 2) 42
3) 45 4) 48
Answer : 45
View Answer

Q2.
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
Answer : Rs.1650
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

Q3.
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
Answer : 2 : 1
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

Q4.
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
Answer : 48
View Answer

Q5.
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
Answer : Rs.6000
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

Q6.
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
Answer : 7 : 5
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

Q7.
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
Answer : 81 litres
View Answer

Q8.
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
Answer : 3 : 5
View Answer

Q9.
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
Answer : Can't be determined
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

Q10.
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
Answer : 2 litres
View Answer

Previous123Next