advance math mcq pdf Model Questions & Answers, Practice Test for ibps rrb so officer sclae 2 3 single exam 2024

Answer: (d)

Two possibilities are there :

(i) Chemistry part I is available in 8 books with Chemistry part II. or

(ii) Chemistry part II is available in 8 books but Chemistry part I is not available.

Total No. of ways

= 1 × $^6 C_1 + ^7 C_3$

= $6 + {7 × 6 × 5}/{3 × 2}$ = 6 + 35 = 41

Answer: (a)

Total no. of outcomes when two dice are thrown = n (S)

= 36 and the possible cases for the event that the sum of numbers on two dice is a prime number, are

(1, 1), (1, 2), (1, 4), (1, 6), (2, 1), (2, 3), (2, 5), (3, 2), (3, 4), (4, 1), (4, 3), (5, 1), (5, 6), (6, 1), (6, 5)

Number of outcomes favouring the event = n (A) = 15

Required probability = ${n(A)}/{n(S)} = {15}/{36} = 5/{12}$

Answer: (b)

Since in 221 games each boy plays exactly one game with each girl,

So, mn = 221 (1)

as, m > n > 1, so only m = 17 and n = 13 satisfies (1)

∴ Total no of students = m + n = 17 + 13 = 30

Number of games in which both players are girls = $^{13}C_2$ = 78

Answer: (a)

No of different sums of money = any 1 coin at a time + any 2 coins + any 3 coins it all 4 coins

= $^4C_1 + ^4C_2 + ^4C_3 + ^4C_4$

= 4 + 6 + 4 + 1 = 15

Answer: (a)

Under the given restrictions, 5 questions can be selected in the following ways :

2 questions from the first section and 3 questions from the second section

OR

3 questions from the first section and 2 questions from the second section.

Required no. of ways = $^4C_2 × ^4C_3 + ^4C_3 × ^4C_2$

= 24 + 24 = 48