1) When a positive integer is expressed in base 7, it is AB base 7 , and when it is expressed in base 5, it is BA base 5. What is the positive integer in decimal?

Guest May 26, 2019

#1**+1 **

I went 7A + B = 5B + A

thus 6A = 4B

From this I concluded that A and B are 4 and 6.

(base 7) 46 = (base 10) 28 + 6 = 34

(base 5) 64 = (base 10) 30 + 4 = 34

The question is what is the integer in decimal. It's **34**.

.

Guest May 27, 2019

edited by
Guest
May 27, 2019

#2**+1 **

(Guest: Note....you cannot have a 64_{5} ..... there is no '6' in base 5 )

See other answers here:

https://web2.0calc.com/questions/help-please_24894

ElectricPavlov May 27, 2019

edited by
Guest
May 27, 2019