1. If a and b are positive integers such that
ab = 125, then (a - b)a+b-4 is equal to
(A) 25. (B) 16.
(C) 28. (D) 30.
2. The sum of the digit of a number 10n � 1 is
3798. The value of n is :
(A) 422 (B) 431
(C) 501 (D) 673

Asked by Dhruvpunglia135 | 11th Apr, 2019, 09:14: PM

Expert Answer:

The question which you have posted should be like below....
ab = 125, then (a - b)a + b - 4 is equal to
ab = 125
53 = 125
a = 5 and b = 3
(a - b)a + b - 4 = (5 - 3)5 + 3 - 4  = 24 = 16

Answered by Sneha shidid | 12th Apr, 2019, 09:48: AM