Question

12. Find the largest number of three digits exactly divisible by 15, 18, 27 and 30. RRB NTPC (Phase 1) 2016 (1) 870 (2) 900 (3) 810 (4) 780

11th - 12th Class

Maths

Solution

162

4.0 (1 ratings)

12. (3) : The largest number of three digits [ =999 ] ( therefore ) LCM of begin{tabular}{c|c} ( 15, ) & 18,27 and 30 2 & 15,18,27,30 hline 3 & ( 15, ) & 9,27,15 hline 3 & ( 5, ) & 3,9,5 hline 3 & ( 5, ) & 1,3,5 hline 5 & ( 5, ) & 1,1,5 hline & 1,1,1,1 & end{tabular} [ begin{array}{l} =2 times 3 times 3 times 3 times 5 =270 end{array} ] Again, [ 2 7 0 longdiv { 9 9 9 } 3 ] ( frac{810}{189} ) ( therefore ) Required number ( =999-189=810 )