Question

Make the greatest and the smallest 4-digit numbers using the digits 5, 4, 7 and 9 (without repeating the digits) and with the condition that:

(i) 7 is at unit’* place.

(ii) 9 is at ten’* place

(iii) 4 is at hundred’* place

Answer 1

*(i) 7 is at unit’ place**

The smallest 4-digit number using the digits 5, 4, 7 and 9, and keeping 7 at unit’* place = 4597

The greatest 4-digit number using the digits 5, 4, 7 and 9 and keeping 7 at unit’* place = 9547

*(ii) 9 is at ten’ place**

The smallest 4-digit number using the digits 5, 4, 7 and 9 and keeping 9 at ten’* place = 4597

The greatest 4-digit number using the digits 5, 4, 7 and 9 and keeping 9 at ten’* place = 7594

*(iii) 4 is at hundred’ place**

The smallest 4-digit number using the digits 5, 4, 7 and 9 and keeping 4 at hundred’* place = 5479

The greatest 4-digit number using the digits 5, 4, 7 and 9 and keeping 4 at hundred’* place = 9475