Directions: Each of the questions given below is followed by series of options among which you have to choose the best one. You can also review your choices by clicking into answer section.
1. A certain amount was divided between Santosh and Rajan in the ratio of 4 : 3. If Rahim’s share was Rs.2400, the total amount was.
A. Rs. 5600
B. Rs. 9600
C. Rs. 3200
D. Rs. 16800
Answer
Explanation:
Let S = 4x and R = 3x.
Total amount = 7x.
Then, 3x = 2400 so x= 800.
Total amount = 7x = Rs.5600
2. The number of seats available for Biology and Computer Science in a school is in the ratio 5:8. They are to be increased by 30% and 25% . Find the new ratio.
A. 6:10
B. 13:20
C. 3:4
D. 35:33
Answer
Explanation:
Let the number of seats be 5x and 8x.
New ratio = (1.3*5x):(1.25*8x) = 6.5x:10x = 13:20
3. Two numbers are respectively 20% and 50% more than a third number. The ratio of the two numbers is:
A. 2 : 5
B. 3 : 5
C. 4 : 5
D. 6 : 7
Answer
Explanation:
Let the third number be x.
Then, first number = 120% of x =(120x/100)=6x/5
Second number = 150% of x =(150x/100)=3x/2
Ratio of first two numbers =(6x/5): (3x/2)= 12x : 15x = 4 : 5.
4. According to a recipe, 400 grams of flour should be mixed with 500 grams of sugar to bake cookies. If I have only 300 grams of flour, how much sugar should I mix to maintain the same proportion?
A. 360
B. 380
C. 375
D. 400
Answer
Explanation:
Flour and sugar have to mixed in the ratio 4:5
4:5:: 300:x
4x=1500
x=375
375 grams of sugar should be mixed.
5. The salaries A, B, C are in the ratio 2 : 3 : 5. If the increments of 15%, 10% and 20% are allowed respectively in their salaries, then what will be new ratio of their salaries?
A. 3 : 3 : 10
B. 10 : 11 : 20
C. 23 : 33 : 60
D. Cannot be determined
Answer
Explanation:
Let A = 2k, B = 3k and C = 5k.
A's new salary = 115of 2k =(115/100)x 2k=(23k/10)
B's new salary = 110of 3k =(110x 3k)/100)=33k/10
C's new salary = 120of 5k =(120x 5k)/100= 6k
New ratio (23k/10): (33k/10) : 6k= 23 : 33 : 60
6. Three quantities X, Y and Z are such that XY=kZ where k is constant. Initially, X was at 4 and X:Y:Z was 2:3:4. If the value of Y is changed to 12 and Z is kept constant, find the value of X.
A. 2
B. 3
C. 5
D. 6
Answer
Explanation:
X:Y:Z=2:3:4
X=4 Then, Y=6, Z=8
XY=kZ
4*6=k*8
8k=24
k=3,
Then Y=12, Z=8
X*12=3*8
X=2
7. If p : q = 3 : 4 and q : r= 8 : 9, then p : r is :
A. 1: 3
B. 2 : 3
C. 3 : 2
D. 1: 2
Answer
Explanation:
p/r = (p/q) * (q/r) = (3/4) * (8/9) = 2/3
So, p : q = 2:3
8. 4 singers, 5 dancers and 3 comperes divide an amount of Rs.130000 among themselves such that 3 comperes get as much as 2 dancers and 3 dancers get as much as 2 singers. Find the amount received by a singer.
A. Rs.18000
B. Rs.13000
C. Rs.15000
D. Rs.10000
Answer
Explanation:
4S+5D+3C=130000
3C=2D
3D=2S
S=3D/2
[4*(3D/2)]+5D+2D = 130000
6D+5D+2D = 130000
13D = 130000
D = Rs.10000
S=3D/2 = Rs.15000
9. In a mixture 60 liters, the ratio of milk and water 2 : 1. If this ratio is to be 1 : 2, then the quantity of water to be further added is:
A. 20 liters
B. 30 liters
C. 40 liters
D. 60 liters
Answer
Explanation:
Quantity of milk = (60/3) x2 liters = 40 liters.
Quantity of water in it = (60- 40) liters = 20 liters.
New ratio = 1:2
Let quantity of water to be added further be x liters.
Then, milk : water =40/(20 + x) .
Now, 40/(20 + x)= 1/2
20 + x= 80
20 + x = 80
x = 60.
Quantity of water to be added = 60 liters.
10. If a+b : b+c : c+a = 6 : 7 : 8 and a + b + c = 14, then the value of c is : . [C.B.I. 1993]
A. 6
B. 8
C. 7
D. 14
Answer
Explanation:
(a/3) = (b/4) = (c/7) then a = 3k, b = 4k, c = 7k
a+b+c/c = 3k+4k+7k/7k = 14k/7k = 2
11. Two number are in the ratio 3 : 5. If 9 is subtracted from each, the new numbers are in the ratio 12 : 23. The smaller number is:
A. 27
B. 33
C. 49
D. 55
Answer
Explanation:
Let the numbers be 3x and 5x.
Then, (3x – 9)/(5x – 9) =(12/23)
or, 23(3x – 9) = 12(5x – 9)
or, 9x = 99
Therefore, x = 11.
The smaller number = (3 x 11) = 33.
12. Rs. 120 are divided among A, B, C such that A’s share is Rs. 20 more than B’s and Rs. 20 less than C’s. What is B’s share?
A. Rs. 10
B. Rs. 20
C. Rs. 15
D. Rs. 25
Answer
Explanation:
Let C = x. Then A = (x—20) and B = (x—40).
or, x + x – 20 + x – 40 = 120
or, x=60.
A:B:C = 40:20:60 = 2:1 :3.
B’s share = Rs.120*(1/6) = Rs. 20.
13. Seats for Mathematics, Physics and Biology in a school are in the ratio 5 : 7 : 8. There is a proposal to increase these seats by 40%, 50% and 75% respectively. What will be the ratio of increased seats?
A. 2 : 3 : 4
B. 6 : 7 : 8
C. 6 : 8 : 9
D. None of these
Answer
Explanation:
Originally, let the number of seats for Mathematics, Physics and Biology be 5x, 7x and 8x respectively.
Number of increased seats are (140% of 5x), (150% of 7x) and (175% of 8x).
(140/100)* 5x , (150/100)* 7x and (175/100)* 8x
7x , (21x/2) and 14x
The required ratio = 7x : (21x/2) : 14x
= 14x : 21x : 28x
= 2 : 3 : 4.
14. An alloy is to contain copper and zinc in the ratio 9 :4. The zinc required (in kg) to be melted with 24 kg of copper, is 7
A. 10 and 2/3
B. 9 and 2/3
C. 10 and 1/3
D. 9
Answer
Explanation:
9:4: 24 : x
⇒ 9x = 4 * 24
⇒ x = (4*24)/9 = 32/3 Kg. hence 10 and 1/3
15. A class has 90 students. If the ratio of boys and girls is 7:8, find the number of boys in the class.
A. 48
B. 42
C. 60
D. 70
Answer
Explanation:
7x+8x=90
or, 15x=90
So, x=6
Number of boys=7x=42
