Question

12. Find the least number which on decreasing by 20 is exactly divisible by 18, 21,28 and 30​

Answer 1

Step-by-step explanation:

First , we find the least number which is exactly divisible by the numbers 18,21,28 and 30 . For this , we find the L.C.M of 18,21,28 and 30.

$l.c.m \: = 2 \times 2 \times 3 \times 3 \times 5 \times 7 = 1260$

According to given , the required will be 20 more than 1260.

$The \: required \: number = 1260 + 20 = 1280</p><p></p><p>$

pls mark as brainlist