Question

A two digit number is such that the product of its digits is 35.When 18 is added to the
number, the digits interchange their places. Find the number.

Answer 1

Answer:

57

Step-by-step explanation:

10a+b is the number

------------------

• ab=35

• 10a+b+18=10b+a ⇒9a+18=9b ⇒ b=a+2
• a(a+2)=35 ⇒ a²+2a+1=36 ⇒ (a+1)²=6² ⇒ a+1=6 ⇒ a=5 ⇒ b=7

Answer: number is 57