More Mods

What is the units digit for the number 123^(456) ?

Expenses

What is the largest number which, when divided into 1905, 2587, 3951, 7020 and 8725 in turn, leaves the same remainder each time?

Factorial

How many zeros are there at the end of the number which is the product of first hundred positive integers?

Galley Division

Stage: 4 Challenge Level:

 $15$ goes into $47$ three times $3 \times 1 = 3$ $4 - 3 = 1$ $3 \times 5 = 15$ $17 - 15 = 2$ Write $15$ again $15$ goes into 23 once $1 \times 1 = 1$ $2 - 1 =1$ $1 \times 5 = 5$ $13 - 5 =8$

... and so on until:

$47324 \div 15 = 3154$ rem $14$