Mathmetics
ISBT Mathmetics for all banking PO,Clerk,IBPS PO,Railway,SSC,IAS,OAS Exams
Q1. |
|
1) | 72 | 2) | 80 |
3) | 100 | 4) | 120 |
5) | None of these |
Answer : 100
Explanation :
Explanation :
Let, the Total Number of Students be x.
20% of Students are below 8 years of age.
The Number of Students above or equal 8 years of age =80% of x............(i)
Number of Students of 8 years of age = 48 .....(ii)
Number of Students above 8 years of age = 2/3 × Number of Students of 8 years of age.
Number of Students of 8 years of age.
Number of Students above age of 8 =2/3 × 48=32---(iii)
From equation (i), (ii) and (iii),
80% of x = 48+2/3 of 48
80% of x = 80
x = 100.

Q2. |
|
1) | 60 | 2) | 70 |
3) | 72 | 4) | 80 |
5) | None of these |
Answer : 80
Explanation :
Explanation :
Let, the total Maximum marks in exam = 100%
His score = 50% of 100 = 50
His marks after review = 140% of 50 = 70
His marks after post review = 120% of 70 = 84
A.T.Q 84% – 12 =70% + 30
14% = 42
or 100% = 300
So passing marks = 300(70/100) + 30 = 240
Total marks = 100% = 300
Thus, required percentage score needed for passing the examination = (240/300 ) X 100 = 80%

Q3. | A vendor buy Fresh Fruits, contain 70% water and also buy Dry Fruits which contain 40% water. If he buys 120 kg of Fresh Fruits,how much quantity of Dry Fruits can be obtains from that quantity? |
1) | 56 kg | 2) | 60 kg |
3) | 64 kg | 4) | 72 kg |
5) | None of these |
Answer : 60 kg
Explanation : Given ,total quantity of fresh fruits = 120 kg
Explanation : Given ,total quantity of fresh fruits = 120 kg
In the fresh fruits , water contain = 120 x (70/100 ) = 84 kg and non-water contain = 120-84 = 36 kg.
In the Dry fruits, water contain = 40% and non-water contain 60%.
Since, Non-water quantity is always constant i.e.
60% = 36 kg
or 100% = (36/60) x 100 = 60 kg
Thus , Dry fruits quantity = 60 kg in 120 kg of Fresh fruits .

Q4. |
|
1) | 12.5% | 2) | 17.5% |
3) | 19% | 4) | 21% |
5) | None of these |
Answer : 19%
Explanation : Allegation Method:
Explanation : Allegation Method:
10% (C) x% (D)
15% (M)
(D-M) = x-15 (M-C) = 15 -10=5
So, x-15 / 5 = 4/5
or x =15+4= 19%

Q5. | When 20% of a number added to another number, the second number increases by its 50%. what is the ratio between two numbers ? |
1) | 2:5 | 2) | 5:2 |
3) | 2:3 | 4) | 3:4 |
5) | None of these |
Answer : 5:2

Q6. |
|
1) | 425 | 2) | 480 |
3) | 520 | 4) | 625 |
5) | None of these |
Answer : None of these
Explanation : Let, the full mark be 100%.
Explanation : Let, the full mark be 100%.
A boy should requires marks to pass = 483 +117 = 600
So, the full mark = 600 i.e. 100%
So, the required mark for a girl should = (600/40) x 35 = 525

Q7. |
|
1) | Rs.3200 | 2) | Rs.3126 |
3) | Rs.3136 | 4) | Rs.3048 |
5) | None of these |
Answer : Rs.3136
Explanation :
Explanation :
Let, the total amount of money with Alok be Rs.x .
x = (504 x 100)/[100 - (23+33+19+16) ]= Rs. 5600
Reqd. amount of money
= ( Rs. 5600 x 56)/100= Rs. 3136

Q8. | A shopkeeper wants to buy 600 kg watermelon,contain 99% water. On the way of shipping due to dehydration ,it contain only 98% water when it reaches at the destination. What is the present mass of the watermelon ? |
1) | 294 kg | 2) | 300 kg |
3) | 494 kg | 4) | 588 kg |
5) | None of these |
Answer : 300 kg
Explanation : Given, Original weight watermelon is 600 kg .
99% water i.e. 600X99/100= 594 kg and 6 kg non-water substance.
After, dehydration, now 98% water in new content.
But non-water substance remain constant. In the new content, water contain 2% and non-water contain 98%.
So, 2% = 6kg.
Or 98% = (6/2) X 98 =294 kg.
Therefore, present mass = 294+6= 300kg.
Explanation : Given, Original weight watermelon is 600 kg .
99% water i.e. 600X99/100= 594 kg and 6 kg non-water substance.
After, dehydration, now 98% water in new content.
But non-water substance remain constant. In the new content, water contain 2% and non-water contain 98%.
So, 2% = 6kg.
Or 98% = (6/2) X 98 =294 kg.
Therefore, present mass = 294+6= 300kg.

Q9. | There are 480 students in a class, consists of boys and girls, appearing in an examination. 85% of girls and 70% of boys pass in that examination. How many boys pass in the examination, if over all 75% of the students pass in that examinations ? |
1) | 224 | 2) | 216 |
3) | 236 | 4) | 244 |
5) | None of these |
Answer : 224
Explanation : Let, boys are x. So, girls are (480 -x).
Explanation : Let, boys are x. So, girls are (480 -x).
Then, 70x/100 + 85(480 -x)/100 = 480 (75/100)
or (70x + 408,00 - 85x) = 36,000
or -15x = -4800
or x =320
So, boys pass = 320 X 70/100 = 224

Q10. | When 30% of a number added to another number , the second number is increases by 50%.What is the ratio between the first number to second number ? |
1) | 3:5 | 2) | 5:3 |
3) | 2:3 | 4) | 4:5 |
5) | None of these |
Answer : 5:3
Explanation : Let, two numbers are x and y respectively.
Explanation : Let, two numbers are x and y respectively.
So, 30x/100 + y = y +50y/100
or 3x = 5y
or x:y = 5:3
