Unilorin Post-UTME Mathematics 2015 (Model questions) Question 26

Question 26

Linear and Simultaneous Equations

A three-digit number is such that the sum of its digit is 12. The middle is half the sum of the other two and the last digit is three times the first one. Find the number

A.642
B.246
C.264
D.662

Show the answer and explanation

Answer: B (246)

Explanation

Let the first digit be x: the last is 3x and the middle is 2x, so 6x = 12, x = 2, giving 246.