BECE Mathematics 2018 Paper

Concept:The L.C.M. is the smallest number that is exactly divisible by all the given numbers.Explanation:Find the prime factorisation of each number.$10 = 2 \times 5$$15 = 3 \times 5$$25 = 5 \times 5 = 5^2$For L.C.M., take each prime factor with its highest power appearing in any factorisation.The prime factors involved are $2$, $3$ and $5$.The highest power of $5$ is $5^2$.So, L.C.M. $= 2 \times 3 \times 5^2$$= 6 \times 25 = 150$Therefore, $150$ is the least common multiple of $10$, $15$ and $25$.Answer:C. 150