NIELIT 2019 Feb Scientist D - Section C: 15

Question

$21$ mango trees, $42$ apple trees and $56$ orange trees have to be planted in rows such that each row contains the same number of trees of one variety only. Minimum number of rows in which the above trees may be planted is :

• A. $3$
• B. $15$
• C. $17$
• D. $20$

Answer 1

HCF of 21, 42 and 56 is 7.

“each row contains the same number of trees”. So Number of trees = 7

And Now each row contains the same number of trees of “one variety only”.

So, 21 mango trees have 3 rows.

42 apple trees have 6 rows

and 56 orange trees have 8 rows.

Total Rows= 3+6+8 = 17