Class 11th maths set theory part11

If 7 times the 7th term of an AP is equal to 11 times its 11th term, then its 18th term will be

In a certain mathematics class, the part of the class that are members of the math club is 50% of the rest of that class. The total number of math club members in this class is what percent of the entire class?

If 7 times the 7th term of an A.P. is equal to 11 times its 11th term, show that the 18th term of the A.P. is zero.

Find the 20th term of the AP whose 7th term is 24 less than the 11th term, first term being 12.

The 26th, 11th and the last terms of an AP are, 0, 3 and -(1)/(5) , respectively. Find the common difference and the number of terms.

While calculating mode the following observation are found. Lower limit of modal class =40, frequency of modal class =20, frequency of previous class =12 , frequency of preceding class =11 and width of the class =10, find mode .

July 11th is observed as

The ratio of the 11th term to the 18th term of an AP is 2 : 3 . Find the ratio of the 5th term to the 21st term and also the ratio of the sum of the first five terms to the sum of the first 21 terms.