Explanation

Finding the pattern:

6−4=2

9−6=3

13−9=4

The differences between consecutive numbers are +2, +3, +4.

Following this pattern, the next difference should be +5.

So, 

13+5=18.

Explanation

2nd leader of Israel to visit India 

Explanation

Ronaldo made his career in 1998. At age 20.

Ronaldo confirmed his retirement from football on 16 January 2018.

Ronaldo belongs to Portuguese.

Explanation

He fought Iraq war and war in Afghanistan

Service __ United States marine corps

Explanation

Capital _ Abu Dhabi

Currency_ Dirham

Explanation

By China National space administration (CNSA) to send a Rebotice space craft

Explanation

UN office on drugs established in 1997

HQ_ Vienna ,Austria

Explanation

The edge of paper page and columns is known as margin.

Explanation

The mean is calculated by dividing the sum of the terms by the number of terms.

Mean=Sum of the terms/Number of terms​

Given that the mean is 40 and there are 7 terms, we can find the sum as:

40=The sum of the terms/7​

Multiplying both sides by 7:

$$\text{Sum of the terms}=40\times 7=280$$

Explanation

Died on 20 Nov 1910

Famous book war and peace