A two-digit number has digit sum 9. When 27 is subtracted, the digits interchange. If the units digit is u, the number's tens digit is 9-u and one valid number is:
Identify it.

Question

A two-digit number has digit sum 9. When 27 is subtracted, the digits interchange. If the units digit is u, the number's tens digit is 9-u and one valid number is: Identify it.

Accepted Answer

63. Digits sum 9: tens t, units u, t+u=9. (10t+u)-27 = 10u+t gives 9t-9u=27, t-u=3. With t+u=9: t=6,u=3. Number 63.

A two-digit number has digit sum 9. When 27 is subtracted, the digits interchange. If the units digit is u, the number's tens digit is 9-u and one valid number is:
Identify it.

Step-by-Step Solution

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More Class 10 Quadratic Word Problems practice

A two-digit number has digit sum 9. When 27 is subtracted, the digits interchange. If the units digit is u, the number's tens digit is 9-u and one valid number is:Identify it.

Step-by-Step Solution

Master this chapter in 30 minutes a day.

More Class 10 Quadratic Word Problems practice

A two-digit number has digit sum 9. When 27 is subtracted, the digits interchange. If the units digit is u, the number's tens digit is 9-u and one valid number is:
Identify it.