Question

(v) A gardener wants to plant trees in equal rows of 15, 30 and 60. How many minimum
numbers of trees he should have?
a) 40
b) 60
c) 80
d) 120
​

Answer 1

Option (b) 60 is the correct answer.

Given,

Row 1 = 15

Row 2 = 30

Row 3 = 60

To Find,

The minimum numbers of trees he should have =?

Solution,

By factorization of 15,30 and 60, we get

15 = 3 x 5

30 = 2 x 3 x 5

60 = 2 x 2 x 3 x 5

The common factors = 2 x 2 x 3 x 5

Therefore, the lease common factor = 2 x 2 x 3 x 5 = 60

LCM of 15, 30 and 60 = 60

Hence, the minimum number of trees he should have is 60.