Find Percentage

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Q / প্ৰশ্ন:  If 36% of x = 81% of y, find the value of x : y. যদি xৰ 36% = yৰ 81% হয়, তেন্তে x : y কিমান?

Solⁿ / সমাধান:

36% of x = 81% of y, xৰ 36% = yৰ 81%

36/100 x = 81 / 100 y, Cancel 100 on both sides, দুয়োফালৰ পৰা 100 কাটিলোঁ

36x = 81y , Divide both sides by 9, দুয়োফাল 9ৰে ভাগ কৰোঁ

4x = 9y

So, সেয়ে,

x:y = 9:4 

Ans / সঠিক উত্তৰ: (B) 9 : 4

Q. If 12% of a = 25% of b, find the value of a : b. যদি aৰ 12% = bৰ 25% হয়, তেন্তে a : b কিমান ?

Solⁿ / সমাধান:

12% of a = 25% of b, a ৰ 12% = bৰ 25%

12/100 a = 25/100 b, Cancel 100 on both sides. দুয়োফালৰ পৰা 100 কাটিলোঁ

12a = 25b

So, সেয়ে,

 a:b = 25:12 

Ans / উত্তৰ: (A) 25 : 12

Q1. In an examination, 34% of the students failed in Mathematics and 42% failed in English. If 20% of the students failed in both Mathematics and English, what percentage of students passed in both subjects ?

Options: A. 50%  B. 44%  C. 54%  D. 56%

Solⁿ:

1. Let the total number of students = 100%


2. Percentage of students who failed in at least one subject: 34% + 42% - 20% = 56%


3. Percentage of students who passed in both subjects: 100% - 56% = 44%

Ans: 44%

Venn Diagram Idea (Concept)

Draw two circles : Left circle → Math fail (34%), Right circle → English fail (42%). Overlapping part → Both fail (20%)

Calculation: Only Math fail = 34 − 20 = 14%, Only English fail = 42 − 20 = 22%, At least one fail = 14 + 20 + 22 = 56%, So, Passed in both = 100 – 56 = 44%

Practice MCQS

Q2. In a test, 30% students fail in Math, 40% fail in English, and 10% fail in both. What percent pass in both subjects ?

A. 30%   B. 40%   C. 50%   D. 60%

Solⁿ: 100 − (30 + 40 − 10) = 50%

Ans: C. 50%  

Q3. 25% fail in Science, 35% fail in Math, and 15% fail in both. What percent pass in both ?

A. 45%  B. 55%  C. 60%  D. 65%

Solⁿ: 100 − (25 + 35 - 15) = 55%

Ans: B. 55% 

Q4. If 48% fail in Hindi, 52% fail in English, and 20% fail in both, then pass in both is:

A. 20%  B. 32%  C. 48%  D. 20%

Solⁿ: 100 - (48 + 52 - 20) = 32%

Ans: B. 32%