a) How many numbers are there in the '30^(th) ' row of this number pyramid?
b) Which is the last number in' the '30^(th) ' row?
c) Which is the first number' in the '30^(th)' row?
d) What is the sum of all terms in the first 30 rows?

. Which is the first number in the 30^(th) row?

How many prime numbers are there below 30?

Write the first and the last numbers of the 10^(th) line.

What is the sum of first 30 natural numbers?

a) How many two digit numbers are there in all? b) If we choose one number from the two digit numbers, what is the probability that the sum of the digits of that number will be 10 ?

Consider the numbers between 100 and 300 which leave remainder 2 on division by 3 a) Which is the first number in this sequençe? b) Which is the last number in this sequence? c). How many such numbers are there in this sequence? d) Find the, sum of all numbers in the sequence.

The mean of 31 numbers is 36.The mean of first 16 numbers is 32 and that of the last 16 numbers is 40. Then which is the 16^(th) number?