76. .

1. 1. 17

   
   
   

   2. 13

   
   
   

   3. 23

   
   
   

   4. 37

   
   
   

   5. 73

   
   
   

---

1. View Hint View Answer Discuss in Forum

   All numbers are prime numbers but when we reverse the digits all except 23 remain prime numbers.

   Correct Option: C

   All numbers are prime numbers but when we reverse the digits all except 23 remain prime numbers.

---

77. .

1. 1. 143

   
   
   

   2. 133

   
   
   

   3. 131

   
   
   

   4. 87

   
   
   

   5. 57

   
   
   

---

1. View Hint View Answer Discuss in Forum

   131 is the odd one out as it is the only prime number.

   Correct Option: C

   131 is the odd one out as it is the only prime number.

---

---

78. .

1. 1. 126

   
   
   

   2. 217

   
   
   

   3. 345

   
   
   

   4. 513

   
   
   

   5. 730

   
   
   

---

1. View Hint View Answer Discuss in Forum

   All the numbers except 345 are one more than the cube of a certain number.

   Correct Option: C

   All the numbers except 345 are one more than the cube of a certain number.

---

79. .

1. 1. 27

   
   
   

   2. 64

   
   
   

   3. 125

   
   
   

   4. 144

   
   
   

   5. 256

   
   
   

---

1. View Hint View Answer Discuss in Forum

   144 is the square of 12 whereas the rest are cube of certain numbers.

   Correct Option: D

   144 is the square of 12 whereas the rest are cube of certain numbers.

---

---

80. .

1. 1. 11

   
   
   

   2. 13

   
   
   

   3. 15

   
   
   

   4. 17

   
   
   

   5. 29

   
   
   

---

1. View Hint View Answer Discuss in Forum

   All numbers are prime numbers except 15.

   Correct Option: C

   All numbers are prime numbers except 15.

---