Out of four consecutive prime numbers, the product of first three is 105 and the product of last three is 385. Find the last number.

Let us take 4 consecutive prime numbers 3, 5, 7, 11

Product of first three $\Rightarrow 3\times 5\times 7=105$

Product of last three $\Rightarrow 5\times 7\times 11=385$

            Last number is 11