Find the largest five digit number that is divisible by 7,10,15,21 and 28 .

see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.

An Intiative by Sri Chaitanya

75758

-75758

-99960

99960

answer is D.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

Concept- In mathematics, the least common multiple is sometimes referred to as LCM or the lowest common multiple. The smallest number among all the common multiples of the provided numbers is the least common multiple of two or more numbers. Consider the integers 2 and 5. There will be different multiples for each. In order to solve the given question we have to check if number is divisible by all of these numbers, not just divide the number by LCM of these numbers.
Here, five digit largest number is 99999.
And, LCM of 7,10,15,21,28 is
7=7
10=2×5
15=3×5
21=3×7
28=2×2×7
Then, 2×2×3×5×7=420
Therefore 99999/420. the remainder is 39. therefore, 99999-39=99960
Here, remainder is 39
Then, 99999-39=99960
Hence, the correct answer is 4) 99960.

Watch 3-min video & get full concept clarity