Question

Make the greatest and the smallest 4-digit numbers using any four different digits with conditions as given
a. Digit 7 is always at ones place
b. Digit 4 is always at tens place
c. Digit 9 is always at hundreds place
d. Digit 1 is always at housands place

Answer 1

For Smallest number -
(a) 7000
(b) 1400
(c) 1190
(d) 1111
For Largest number -
(a) 7999
(b) 9499
(c) 9999
(d) 9991

Answer 2

Answer:

(a) Digit 7 is always at ones place :

For smallest number the thousand digit must be 1 and rest be 0

⇒ Smallest number = 1007

For largest number all the digits must be 9

⇒ Largest number = 9997

(b) Digit 4 is always at tens place :

For smallest number the thousand digit must be 1 and rest be 0

⇒ Smallest number = 1040

For largest number all the digits must be 9

⇒ Largest number = 9949

(c) Digit 9 is always at hundreds place :

For smallest number the thousand digit must be 1 and rest be 0

⇒ Smallest number = 1900

For largest number all the digits must be 9

⇒ Largest number = 9999

(d) Digit 1 is always at thousands place :

For smallest number the thousand digit must be 1 and rest be 0

⇒ Smallest number = 1000

For largest number all the digits must be 9

⇒ Largest number = 1999