A two digit number when 18 added becomes another two digit number with reversed digits. How many such two digit numbers are possible?
Select:
A) 8	B) 7	C) 1	D) 9	E) 0
Let the two digit number be 'ab' and the number formed after adding 18 to it is 'ba'   So ab + 18 = ba   ⇒⇒ (10a + b) + 18 = 10b + a   ⇒⇒ 18 = 9b – 9a   ⇒⇒ 2 = b – a   So we know that ab, ba both are two digit numbers so a, b ≠≠ 0.   Also when b = 9, a = 7; b = 8, a = 6; b = 7, a = 5; b = 6, a = 4; b = 5, a = 3; b = 4, a = 2; b = 3, a = 1   Answer:1
<result>C</result>
A two digit number when 18 added becomes another two digit number with reversed digits. How many such two digit numbers are possible?