Question

In the equation 858 = axb, the numbers a and b are both positive two-digit integers. What is the greatest possible value of a + b

Answer 1

Answer:

A=10x+y

B=10y+x

10B-A=10[10y+x]-10x-y=100y+10x-10x-y=99y

Stmt1: The tens digit of A is 7 i.e 10x=7. But we don't know Y. Insufficient.

Stmt2: The tens digit of B is 6 i.e 10y=6 y=0.6

Q=99y=99*0.6=59.4 Sufficient.

OA B

Answer 2

Answer:

A.M>=GM

(a+b)/2>=(a×b)^1/2

(a+b)=2((858)^1/2)