Maths Quiz For RBI Assistant Exam: Part I

Ques.1

 Anju’s monthly salary is Rs x. She spends 30% of the monthly salary on food, 20% of the remaining salary on Dress, 25% of the remaining salary on misc expenses and saves Rs 1764. Find the total monthly salary of Anju.

A. 2500 Rs

B. 4200 Rs
C. 4000 Rs
D. 3600 Rs
E. 5000 Rs

Ques 2. 

Mohan’s income is 20% more than Mitali’s income. Mitali’s income is 10% less than Antra’s income. Find Mohan’s income is how much % more than Antra’s income?
A. 20%
B. 15%
C. 10%
D. 8%
E. 12%

Ques 3.

The cost price of a fan is Rs a and the cost price of a cooler is Rs (a + 2000). A shopkeeper sold a fan at a loss of 10% and a cooler at a profit of 20%. He earns total Rs 840 on this deal. Find the ratio of the cost price of fan to that of the cost price of cooler.

A. 11:16
B. 12:17
C. 2:3
D. 5:9
E. None of these

Ques 4. 

Vansh can do a piece of work in 36 days and Tanisha can the same work in 18 days. Vansh started the work alone and after 9 days Tanisha joins Vansh. In how many days will the total be completed?
A. 15 days
B. 10 days
C. 9 days
D. 20 days
E. 12 days

Ques.5 

A man is travelling by car. He covers 120 km distance at a speed of 15 km/h, 150 km distance at a speed of 30 km/h and another 90 km at a speed of 18 km/h. Find his average speed.
A. 25 km/h
B. 15 km/h
C. 20 km/h
D. 18 km/h
E. 10 km/h

Ques 6 

In how many ways a word HEADLIGHT can be arranged so that all the consonant come together?
A. 11520
B. 5760
C. 8640
D. 1440
E. None of these

Ques 7

In a box there are 5 green, 6 yellow and 4 white balls. 5 balls are drawn randomly. What is the probability that 2 are yellow and 3 are green?
A. 20/37
B. 50/1001
C. 50/963
D. 99/1001
E. None of these

Ques 8. 

The area of the circle is 38.5 cm. If the side of the square is 2.5cm more than the radius of the circle. Find the Perimeter of the circle.
A. 56cm
B. 100cm
C. 20cm
D. 24cm
E. 120cm

Ques 9. 

 In a mixture of 72 litres of milk and water, water is 25%. if 9 litres mixture taken out and the same quantity of milk is added. Find the % of milk in new mixture.
A. 50%
B. 87.5%
C. 75%
D. 56%
E. None of these

Ques 10. 

The present average age of Geeta and Sonali is 28 years. The ratio of their ages before 4 years ago was 5 : 7. What will be the ratio of their ages after 8 years?
A. 4:5
B. 2:3
C. 1:2
D. 5:6
E. 7:9

Answers With Solutions

1. Ans. B.

Solution:
Let total monthly salary = 100 Rs.
Expenses on Food = 100 × 30% = 30 Rs
Expenses on Dress = 70 × 20% = 14 Rs
Expenses on misc = 56 × 25% = 14 Rs
Saving = 42 Rs
Total Salary = 1764/42 × 100 = 42 Rs

2. Ans. D.

Solution:

Let Antra’s income = 100 Rs
Mitali’s income = 100 × 90% = 90 Rs
Mohan’s income = 90 × 120% = 108 Rs
% less = 8/100 × 100 = 8%

3. Ans. A

Solution:
According to the question,
(a+2000) × 20% - a × 10% = 840
a/5 + 400 – a/10 = 840
a/10 = 840 – 400
a/10 = 440
a = 4400
Ratio = 4400 : 6400 = 11:16

4. Ans. C.

Solution:
Let total work is 36.
Vansh’s 1 day work = 36/36 = 1
Vansh’s 9 day work = 9
Tanisha’s 1 day work = 36/18 = 2
According to the question,
Let Tanisha and Vansh can do the work in x days.
9 + (1 + 2) x =36
9 + 3x = 36
3x = 36 – 9
3x = 27
x = 9 days

5. Ans. C.

Solution:
Total Distance = 120 + 150 + 90 = 360 km
Total time = 120/15 + 150/30 + 90/18 = 8 + 5 + 5 = 18 hours
Average speed = 360/18 = 20 km/h

6. Ans. E.

Solution:
Consonant = HDLGHT
Total ways = 4! × 6! = 4 × 3 × 2 × 1 × 6 × 5 × 4 × 3 × 2 × 1 = 17280

7. Ans. B.

Solution:
Probability = Favourable outcomes/ Total outcomes = 6C2 × 5C315C5
=6×52×1×5×4×33×2×115×14×13×12×115×4×3×2×1 = 50/1001

8. Ans. D.

Solution:
Area of the circle = π r2
38.5 = 22/7 r2
r2 = 12.25
r = 3.5
Side of square = 3.5 + 2.5 = 6cm
Perimeter = 4 × 6 = 24cm

9. Ans. E.

Solution:
Milk = 72 × 75% = 54 litre
Water = 72 – 54 = 18 litre
Milk in new mixture = 54 – 9×75% + 9 = 54 – 6.75 + 9 = 56.25 litre
% = 56.25/ 72 × 100 = 78.125%

10. Ans. A.

Solution:
Total age = 28 × 2 = 56 years
According to the question,
5x+4 + 7x+4 = 56
12x + 8 = 56
12x = 56 – 8
12x = 48
x = 4
Present age = 20 + 4 = 24, 28 + 4 = 32
Ratio after 8 years = 24 + 8 : 32 + 8 = 32 : 40
= 4:5