CBSE Guess > Papers > Important Questions > Class X > Maths > Mathematics By Mr. Sanjay Kumar

Chapter - 5

Q. 51. Find the sum of all the multiples of 7 lying between 1 and 100.

Q. 52. Find the total number of terms and hence the sum of the series: 3 + 11 + 19 + ……………………+ 827.

Q. 53. Find the sum of 51 terms of an A.P. whose second and third terms are 14 and 18 respectively.

Q. 54. Find the sum of first 15 terms of an A.P. whose nth term is equal to (9 – 5n).

Q. 55. If five times the 5th term of an A.P. is equal to 8 times the 8th term, then find the sum of its first 25 terms.

Q. 56. The sum of three numbers in A.P. is 12 and the sum of their cubes is 288. Find the three numbers.

Q. 57. Find the sum of all those integers which are multiples of 5 and lie between 84 and 719.

Q. 58. The 5th and 12th terms of an A.P. are 30 and 65 respectively. Find the sum of its first 20 terms.

Q. 59. If the total sum of all the numbers of the series 25, 22, 19,…….., is 116. Find its last term.

Q. 60. An A.P. consists of 60 terms. If the first and the last terms are 7 and 125 respectively, the find its 32nd term.