Question

please help in question 11 and 12

Answer 1

let two digit's number =10a+b,

where a=3b,.........eq(1),

now
(10a+b)-(10b+a)=36,

9a-9b=36,

then
a-b=4,.......eq(2),

put the value of a from equation first to the equation second, we have

3b-b=4,

2b=4,

then
b=2,

then
a=3×2=6,


therefore
two digit's number=10×6+2=60+2=62