SOLUTIONWhich of the following CANNOT yield an integer when divided by 10 ?
(A) The sum of two odd integers
(B) An integer less than 10
(C) The product of two primes
(D) The sum of three consecutive integers
(E) An odd integer
In order an integer to be divisible by 10=2*5, the integer must be divisible by 2 (and 5), so it must be even, thus an odd integer is never divisible by 10 (or another way, an integer to be divisible by 10 its units digit must be 0, thus it must be even).
To discard other options:
(A) The sum of two odd integers. Not true: for example, 5+5=10 --> 10 IS divisible by 10.
(B) An integer less than 10. Not true: for example 0 IS divisible by 10.
(C) The product of two primes. Not true: 2*5=10 --> 10 IS divisible by 10.
(D) The sum of three consecutive integers. Not true: for example, -1+0+1=0 --> 0 IS divisible by 10.
NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!
PLEASE READ AND FOLLOW: 11 Rules for Posting!!!
RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;
COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat
DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests?
25 extra-hard Quant Tests
GMAT Club Premium Membership - big benefits and savings