Question 20

A number consists of two digits whose sum is 8. If 18 is added to the number, its digits are interchanged. The number is

Solution

Let the number be "XY" .
Given the sum of digits = X + Y = 8.........Equation 1

This XY can be written as : XY = Y(1) + X(10)

Upon adding 18 to XY we get : {10(X) + Y + 18}

Now, it is given this particular number is "YX" i.e it should be equal to {X + 10(Y)}.
Hence, 10(X) + Y + 18 = X + 10(Y)
9X - 9Y = -18
X - Y = (-2)..........Equation 2

By solving both equations : X = 3 & Y = 5.

Therefore, the number is 35.

View More Questions From Number System

MAT Quant Questions | MAT Quantitative Ability

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

MAT DILR Questions | LRDI Questions For MAT

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

MAT Verbal Ability Questions | VARC Questions For MAT

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

Free MAT Topicwise Questions

MAT Logarithms, Surds and Indices

MAT Para Summary

MAT Games and Tournamnents

MAT Progressions and Series

MAT Special Charts

MAT Grammar and Sentence Correction

MAT DI Miscellaneous

MAT Maxima-Minima

MAT Time Speed Distance

MAT Ssc Reasoning

MAT Reading Comprehension

MAT Data Sufficiency

MAT Linear Equations

MAT Functions, Graphs and Statistics

MAT Mensuration

MAT Venn Diagrams

MAT Averages, Ratio and Proportion

MAT Miscellaneous LR

MAT Truth Lie Concept

MAT Table based DI Sets

MAT Simple Interest Compound Interest

MAT Para Jumbles

MAT Quadratic Equations

MAT Number Systems

MAT Profit And Loss

MAT Venn Diagrams

MAT Time And Work

MAT Coins and Weights

MAT Critical Reasoning

MAT Arrangement

MAT Selection With Condition

MAT Coordinate Geometry

MAT Data change over a period

MAT Percentages

MAT DI with connected data sets

MAT Profit and Loss

MAT Odd One Out

MAT Averages Mixtures Alligations

MAT Verbal Ability

MAT Data Interpretation Basics

MAT Quant Based LR

MAT Quant Based DI

MAT Miscellaneous

MAT Time, Speed and Distance

MAT Inequalities

MAT Routes And Networks

MAT Probability, Combinatorics

MAT Number Series

MAT Data Interpretation