LIVE Course for free

Rated by 1 million+ students
Get app now
JEE MAIN 2023
JEE MAIN 2023 TEST SERIES
NEET 2023 TEST SERIES
NEET 2023
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
12 views
in Aptitude by (41.6k points)
closed by
The average marks of 3 girls is 50. The ratio of the marks of 2 girls is 5 : 7. The marks of the third girl is 3 less than the marks of the 1st girl. Find the marks of the 3rd girl.
1. 42
2. 41
3. 39
4. 45

1 Answer

0 votes
by (30.0k points)
selected by
 
Best answer
Correct Answer - Option 1 : 42

Given:

Average marks of 3 girls = 50

The ratio of the marks Girl1 ∶  Girl2 = 5 ∶ 7

Marks of Girl3 = Marks of Girl1 – 3

Formula:

Average = Sum of all observations/Total number of observations

Calculation:

Total marks of 3 girls = 3 × 50 = 150

Let the marks of Girl1 be 5x and Girl2 be 7x 

Girl3 = 5x – 4

Total marks = 5x + 7x + 5x – 3

⇒ 150 = 17x – 3

⇒ 17x = 153

⇒ x = 153/17 = 9 

Marks of Girl1 = 5x = 45

Girl3 = Marks of Girl1 – 3 = 45 – 3 = 42

∴ Marks of Girl3 is 42

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...