Melody

Thanks for the question straight, To be honest I had not thought about it. But:

B can't be zero because 3*8 = 24  but we would need a units digit of 3

So if B=0 then the tens digit of the answer would have to be 4.  But it is not, so b is not equal to 0

That is a nice method Straight :)

\(64^x = 16^{(x−1)}\\ log_2 64^x = log_2 16^{(x−1)}\\ xlog_2 64 =(x-1) log_2 16\\ x*6 =(x-1) *4\\ 6x=4x-4\\ 2x=-4\\ x=-2\\~\\ check\\ LHS=64^{-2}=(2^6)^{-2}=2^{-12}\\ RHS=16^{-2-1}=16^{-3}=(2^4)^{-3}=2^{-12}=LHS \)

3 blarsfs and 18 crobs in a minute

so

6 blarsfs and 36 crobs in 2 minutes

that is

6 blarsfs and 34 crobs +2crobs in 2 minutes

but we are told that there are

7 blarsfs and 2 crobs in two minutes

so

There must be 34 crobs in 1 blarsfs

and

3*34+18 = 120 crobs in a minute

so one crob is a half second

9 blarfs and 6 crobs = 9*34+6  = 312 crobs = 156 seconds

Another answer here:

Thanks Straight,

It is easiest to do these by long multiplcation:

See if you can work through what I have done.

You say "please help" and then ignore answerers when help is given.

What effect do you think this has?

you want      

12*    in any order where * can be 0,3,4,5,6,7,8,9  

 8*3! = 8*6=48

except it cannot start with 0 so it cant be  012 or 021

48-2 = 46 possibilities

Yes that sounds logical.

15 ways      

0.02843 x 100 = 2.843  

were you asked to multiply it by 100?   No you were not.

Leave the decimal point right where it is

So you need the 0.02  but if the next number is 5 or bigger than 5 then the last digit, the 2 will go up one to 3

Here the 3rd digit after the point is 8, which is a big number (bigger or equal to 5) so the 2 goes up to 3

\(0.0 2| \boxed{8}=0.03\qquad \text{To 2 decimal places}\)