This question was previously asked in

UPSSSC Chakbandi Lekhpal Official Paper 1 (Held on : 30 Sept 2019 Shift 1)

Option 2 : 2016

**Given:**

Each year number of trees increased by 10%

**Formula used:**

A = P{1 + (R/100)}^{T}

Where, A = Amount, P = Principal

R = Rate, T = Time

**Calculation:**

Let initially Mahesh had x trees

According to the question, we have

The amount is at least 50% more than x

So, amount = x + 50% of x = 3x/2

Now, according to the formula, we have

(3x/2) = x{1 + (10/100)}T

⇒ (11/10)^{T} = (3/2)

⇒ (1.1)^{T} = (1.5)

(1.1)^{4} = 1.46 < 1.5

(1.1)^{5} = 1.61 > 1.5

So, T = 5 year

Then, after 5 years from 2011, the number of trees will be at least 50% more than the initial number.

**∴ In 2016 the number of trees will be at least 50% more than in 2011.**