Percentages for Bank Exams (SBI, IBPS, RRB)

Ans: A

Explanation: Let the number be x.
The question can be translated into the equation: 150 – 0.30x = 90
Subtract 150 from both sides: -0.30x = 90 – 150
-0.30x = -60
Divide both sides by -0.30: x = -60 / -0.30
x = 200

Ans: B

Explanation: Let P’s savings be ‘P’ and Q’s savings be ‘Q’.
Given: 40% of P = 30% of (2/3) of Q
Also, Q = Rs. 3600
So, 0.40 * P = 0.30 * (2/3) * 3600
0.40 * P = 0.30 * 2400
0.40 * P = 720
P = 720 / 0.40
P = 1800

Ans: A

Explanation: Let A’s salary be ‘x’ and B’s salary be ‘y’.
We know x + y = 40000.
A saves 15% of their salary, which is 0.15x.
B saves 5% of their salary, which is 0.05y.
Since they save the same amount, 0.15x = 0.05y.
Simplifying, we get 3x = y.
Substitute y = 3x in the first equation: x + 3x = 40000.
4x = 40000
x = 10000.

Correct Option: A

Ans: B

Explanation: Let the original number be x.
1. A third of the number is (1/3)x
2. 140% of (1/3)x is (140/100) * (1/3)x = 46.2
3. Solving for x: (14/30)x = 46.2 => x = (46.2 * 30) / 14 => x = 99
4. The difference between 132 and the original number (99) is 132 – 99 = 33
5. The percentage increase is (Difference / Original Number) * 100 = (33/99) * 100 = 33.33%

Correct Option: B

Ans: E

Explanation: Let’s assume the total population is 7+6+5 = 18 units.
Men: 7 units, 70% literate, so 30% illiterate. Illiterate men = 7 * 0.30 = 2.1
Women: 6 units, 20% illiterate, so 80% literate. Illiterate women = 6 * 0.20 = 1.2
Children: 5 units, 80% literate, so 20% illiterate. Illiterate children = 5 * 0.20 = 1.0
Total illiterate = 2.1 + 1.2 + 1.0 = 4.3
Overall illiteracy rate = (Total illiterate / Total population) * 100 = (4.3 / 18) * 100 = 23.89%.
Given the options, the question is aiming to get the calculation close to the answer.

Ans: B

Explanation: Let the man’s initial salary be 6x and the woman’s initial salary be 5x. The man’s salary increases by 20% to reach Rs. 216. Therefore, 6x * 1.20 = 216. Solving for x, we get x = 216 / (6 * 1.20) = 216 / 7.2 = 30.
The woman’s initial salary is 5x = 5 * 30 = Rs. 150.
The woman’s salary increases by 4%, so her new salary is 150 * 1.04 = Rs. 156.

Correct Option: B

Ans: D

Explanation: Let the total number of people in the meeting be x. The percentages of doctors and architects are given as 32% and 54% respectively. This means that the percentage of accountants is 100% – 32% – 54% = 14%. We are given that the number of accountants is 1960. Thus, 14% of x = 1960. We can find x by dividing 1960 by 0.14: x = 1960 / 0.14 = 14000. Now, the number of architects is 54% of 14000 which is 0.54 * 14000 = 7560.
Correct Option: D

Ans: D

Explanation: Let the initial amount of money Sonia had be ‘x’.
Sonia gave 15% to Shabnam and kept 10% for later, so the remaining percentage is 100% – 15% – 10% = 75%.
This 75% was divided between Ankur and Arjun in a 2:3 ratio.
Let Ankur’s share be 2y and Arjun’s share be 3y.
Arjun received Rs. 9000 more than Ankur, so 3y – 2y = 9000
Therefore, y = 9000.
Ankur’s share = 2y = 2 * 9000 = 18000
Arjun’s share = 3y = 3 * 9000 = 27000
The total amount given to Ankur and Arjun is 18000 + 27000 = 45000.
Since this is 75% of the initial amount, we have:
0.75x = 45000
x = 45000 / 0.75
x = 60000
So, Sonia initially had Rs. 60,000.

Correct Option: D

Ans: D

Explanation: Let ‘b’ be the original number of boys and ‘g’ be the original number of girls. We have two equations:

1. b + g = 800 (Total students initially)
2. 1.1b + 1.15g = 900 (Total students after increase)

From equation 1, we can express b as b = 800 – g. Substitute this into equation 2:

1. 1(800 – g) + 1.15g = 900
880 – 1.1g + 1.15g = 900
0.05g = 20
g = 20 / 0.05
g = 400

Therefore, the original number of girls was 400.

Ans: B

Explanation: Let the total marks be ‘T’.
Vaibhav scored 25% of T, which is 0.25T. He needed 32 more marks to pass, so the passing score is 0.25T + 32.
Ravi scored 40% of T, which is 0.40T. He got 28 marks above the passing score, so the passing score is 0.40T – 28.
Since both expressions represent the passing score, we can equate them:
0.25T + 32 = 0.40T – 28
0.15T = 60
T = 60 / 0.15 = 400

Correct Option: B

Ans: D

Explanation: Let’s work backward from the YouTube users:

* YouTube: 6300 users represent the remaining percentage after Amazon, Netflix, and Hotstar.
* Hotstar: Let’s denote the number of users before Hotstar as ‘x’. 30% of ‘x’ were on Hotstar. This means 70% of ‘x’ is equal to YouTube users. Thus, 0.7x = 6300, and x = 6300 / 0.7 = 9000.
* Netflix: The 9000 users represent half of the users remaining after Amazon. Let ‘y’ be the number of users before Netflix. Thus, 0.5y = 9000, and y = 9000 / 0.5 = 18000.
* Amazon: The 18000 users represent 80% of the total users because 20% are on Amazon. Let the total number of members be ‘z’. So, 0.8z = 18000 and z = 18000 / 0.8 = 22500

Correct Option: D

Ans: D

Explanation: Let P be the population in 2019. The population in 2020 would be P * 1.05. The population in 2021 would be (P * 1.05) * 1.05 = P * 1.05^2. We are given that the population in 2021 was 44,100. So, P * 1.05^2 = 44,100. Therefore, P = 44,100 / (1.05^2) = 44,100 / 1.1025 = 40,000.
Correct Option: D

Ans: C

Explanation:
1. **Voters who didn’t vote:** 8000 * 10% = 800 voters
2. **Votes cast:** 8000 – 800 = 7200 votes
3. **Invalid votes:** 7200 * 5% = 360 votes
4. **Valid votes:** 7200 – 360 = 6840 votes
5. **Winning candidate’s votes:** 6840 * 60% = 4104 votes
6. **Losing candidate’s votes:** 6840 – 4104 = 2736 votes