A class consists of a number of boys whose ages are in A.P., the common difference being four months. If the youngest boy is just eight years old and if the sum of the ages is 168 years, then number of boys in the class, are 16    (b)  18      (c)  20   (d) None of these

The present ages of Renu and Ravi are in the ratio 5: 6. The sum of their present ages is 44 in years. The difference of their ages (in years) is (a)4 (b) 5 (c) 8 (d) 2

If the square of differences of three numbers be in A.P., then their differences re in (A) A.P. (B) G.P. (C) H.P. (D) none of these

If four numbers in A.P. are such that their sum is 50 and the greatest number is 4 times the least, then the numbers are (a) 5, 10, 15, 20 (b) 4, 10, 16, 22 (c) 3, 7, 11, 15 (d) none of these

The first three of four given numbers are in G.P. and their last three are in A.P. with common difference 6. If first and fourth numbers are equal, then the first number is a. 2 b. 4 c. 6 d. 8

A and B are friends and their ages differ by 2 years. As father D is twice as old as A and B is twice as old as his sister C. The age of D and C differ by 40 years. Find the ages of A and B.

A and B are friends and their ages differ by 2 years. A’s father D is twice as old as A and B is twice as old as his sister C. The age of D and C differ by 40 years. Find the ages of A and B.

There are two sets A and B each of which consists of three numbers in A.P.whose sum is 15 and where D and d are the common differences such that D-d=1. If p/q=7/8 , where p and q are the product of the numbers ,respectively, and d gt 0 in the two sets . The sum of the product of the numbers in set B taken two at a time is

There are 20 girls and 15 boys in a class.(a) What is the ratio of number of girls to the number of boys?(b) What is the ratio of number of girls to the total number of students in the class?

A class consists of 80 students, 25 of them are girls and 55 are boys. If 10 of them are rich and the remaining are poor and also 20 of them are intelligent, then the probability of selecting an intelligent rich girls is a) 5//128 b) 25//128 c) 5//512 d) none of these

A class consists of 80 students, 25 of them are girls and 55 are boys. If 10 of them are rich and the remaining are poor and also 20 of them are intelligent, then the probability of selecting an intelligent rich girls is a. 5//128 b. 25//128 c. 5//512 d. none of these