Use app×
Join Bloom Tuition
One on One Online Tuition
JEE MAIN 2025 Foundation Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
676 views
in Number System by (237k points)
closed by
While writing all the numbers from 700 to 1000, how many numbers occur in which the digit at hundred's place is greater than the digit at ten's place, and the digit at ten's place is greater than the digit at unit's place? 
1. 61
2. 64
3. 85
4. 91

1 Answer

0 votes
by (239k points)
selected by
 
Best answer
Correct Answer - Option 3 : 85

Given :

Numbers are such that the hundred's place is greater than ten's place and the ten's digit is greater than the unit digit.

Calculations :

(I) Numbers from 700 to 800 where hundred's digit is more than ten' digit are ⇒ 700, 701, 702,.......769 

Numbers from above-written numbers where ten's digit is more than unit's digit are ⇒ 710, 720, 721, 730, 731, 732, 740, 741, 742, 743, 750, 751, 752, 753, 754, 760, 761, 762, 763, 764, 765 

Total such numbers from 700 to 800 are 21 

(ii) Numbers from 801 to 900 where hundred's digit is more than ten's digit are ⇒ 801 to 879 

Numbers from above-written numbers where ten's digit is more than the unit's digit are the same as in the previous group from 700 to 800 up to 869

Other such numbers are ⇒ 870, 871, 872, 873, 874, 875, 876

Total such number from 801 to 900 are 28    (21 + 7)

(iii) Numbers from 901 to 1000 where hundred's digit is more than ten's digit are ⇒ 901 to 989 

Numbers from above-written numbers where ten's digit is more than unit's digit are same up to previous group up to 969

Other such numbers are 970, 971, 972, 973, 974, 975, 976, 980, 981, 982, 983, 984, 985, 986, 987, 

Total such number form 901 to 1000 are 36   (21 + 15)

Now total numbers from 700 to 1000 

⇒ 21 + 28 + 36 

⇒ 85 

∴ Option 3 will be the correct choice. 

 

 

 

 

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

...