Maths Olympiad Prep

Library / /3 of 60

Number theory Difficulty 3.6 AMC 10/12 Find the answer South Africa

If 43504350 is written as a product of its prime factors, then the largest prime factor is

Pick one

Solution

Clearly 43504350 is divisible by 55, since the last two digits are 5050. It is also divisible by 33, since the sum of the digits is divisible by 33. Dividing by 150150 gives a quotient of 2929, which is prime, so the prime factorization is 4350=2×3×52×294350 = 2 \times 3 \times 5^2 \times 29, and the largest prime factor is 2929.

Want a route through all this instead of an archive? The track puts 2,000 problems in a working order, from AMC 10 level to the IMO shortlist.

Source: MathNet, licensed CC-BY-4.0. Statement and solution reproduced as published; topic and difficulty added by this site.