# Bonus problems need it done by TOMMOROW!!

• Nov 5th 2008, 11:02 AM
help123
Bonus problems need it done by TOMMOROW!!
• Nov 5th 2008, 06:20 PM
Soroban
Hello, help123!

Did you even try ?

Quote:

If you take all the prime numbers less than 1,000,000 and multiply them together,
what will be the last digit of the answer?

The primes are: . 2, 3, 5, 7, 11, . . .

Start mutiplying . . .

. . $\begin{array}{ccc}2 \times 3 &=& 6 \\
\times 5 &=& 30 \\ \times 7 &=& 210 \\ \times 11 &=& 2310 \\
\vdots & & \vdots \\ & & duh!\end{array}$

• Nov 6th 2008, 11:51 AM
help123
thank you thank you