Question 53

In a class with a certain number of students, if one student weighing 50 kg is added then the average weight of the class increases by 1 kg. If one more student weighing 50 kg is added then the average weight of the class increases by 1.5 kg over the original average. What is the original average weight (in kg) of the class?

Solution

Let number of students in class be $$x$$ and average weight of class be $$y$$ kg

=> Total weight of class = $$xy$$ kg

According to ques, => $$\frac{xy+50}{x+1}=y+1$$

=> $$xy+50=xy+x+y+1$$

=> $$x+y=49$$ ------------(ii)

Similarly, $$\frac{xy+100}{x+2}=y+1.5$$

=> $$xy+100=xy+1.5x+2y+3$$

=> $$1.5x+2y=97$$ ------------(ii)

Solving equations (i) and (ii), we get : $$x=2$$ and $$y=47$$

$$\therefore$$ Original average weight = 47 kg

=> Ans - (D)

View More Questions From Quant

Create a FREE account and get:

All Quant Formulas and Shortcuts PDF
100+ previous papers with solutions PDF
Top 5000+ MBA exam Solved Questions for Free

maruti sir image

MAT Quant Questions | MAT Quantitative Ability

MAT Mensuration Questions MAT Logarithms, Surds and Indices Questions MAT Probability, Combinatorics Questions MAT Simple Interest Compound Interest Questions MAT Venn Diagrams Questions MAT Profit And Loss Questions MAT Geometry Questions MAT Inequalities Questions MAT Time Speed Distance Questions MAT Time And Work Questions MAT Coordinate Geometry Questions MAT Progressions and Series Questions MAT Number Series Questions MAT Profit and Loss Questions MAT Functions, Graphs and Statistics Questions MAT Averages Questions MAT Remainders Questions MAT Averages, Ratio and Proportion Questions MAT Number Systems Questions MAT Arithmetic Questions MAT Time, Speed and Distance Questions MAT Algebra Questions MAT Averages Mixtures Alligations Questions MAT Logarithms Questions MAT Data Sufficiency Questions MAT Quadratic Equations Questions MAT Percentages Questions MAT Linear Equations Questions

MAT DILR Questions | LRDI Questions For MAT

MAT Coins and Weights Questions MAT Charts Questions MAT 2D & 3D LR Questions MAT Selection With Condition Questions MAT Table based DI Sets Questions MAT Truth Lie Concept Questions MAT DI with connected data sets Questions MAT DI Miscellaneous Questions MAT Quant Based LR Questions MAT Venn Diagrams Questions MAT Data Interpretation Questions MAT Maxima-Minima Questions MAT Data change over a period Questions MAT Miscellaneous LR Questions MAT Quant Based DI Questions MAT Special Charts Questions MAT Arrangement Questions MAT Puzzles Questions MAT Routes And Networks Questions MAT Games and Tournamnents Questions MAT Data Interpretation Basics Questions MAT Scheduling Questions

MAT Verbal Ability Questions | VARC Questions For MAT

MAT Odd One Out Questions MAT Para Jumbles Questions MAT Para Summary Questions MAT Miscellaneous Questions MAT Verbal Ability Questions MAT Reading Comprehension Questions MAT Vocabulary Questions MAT Grammar and Sentence Correction Questions MAT Critical Reasoning Questions