Question
How many distinct positive integer-valued solutions exist to the equation \({\left( {{x^2} - 7x + 11} \right)^{\left( {{x^2} - 13x + 42} \right)}} = 1?\)
- 6
- 8
- 2
- 4
Option: 1
Solution:
Solution:
\({\left( {{x^2} - 7x + 11} \right)^{\left( {{x^2} - 13x + 42} \right)}} = 1\)
We know if \({a^b} = 1\)
\( \Rightarrow a = 1\) and b is any number
or \(a = - 1\) and b is even
\(a > 0\) and b is 0
case \(1:{x^2} - 13x + 42 = 0 \Rightarrow x = 6,7\)
case \(2:{x^2} - 7x + 11 = 1 \Rightarrow {x^2} - 7x + 10 = 0 \Rightarrow \) x=2 or 5
case \(3:{x^2} - 7x + 11 = - 1 \Rightarrow {x^2} - 7x + 12 = 0\)
\( \Rightarrow \) x=4 or 3
Hence number of solutions are 6
CAT 2020 Quant questions with Solutions
- CAT 2020 Quant Question 1
- CAT 2020 Quant Question 2
- CAT 2020 Quant Question 3
- CAT 2020 Quant Question 4
- CAT 2020 Quant Question 5
- CAT 2020 Quant Question 6
- CAT 2020 Quant Question 7
- CAT 2020 Quant Question 8
- CAT 2020 Quant Question 9
- CAT 2020 Quant Question 10
- CAT 2020 Quant Question 11
- CAT 2020 Quant Question 12
- CAT 2020 Quant Question 13
- CAT 2020 Quant Question 14
- CAT 2020 Quant Question 15
- CAT 2020 Quant Question 16
- CAT 2020 Quant Question 17
- CAT 2020 Quant Question 18
- CAT 2020 Quant Question 19
- CAT 2020 Quant Question 20
- CAT 2020 Quant Question 21
- CAT 2020 Quant Question 22
- CAT 2020 Quant Question 23
- CAT 2020 Quant Question 24
- CAT 2020 Quant Question 25
- CAT 2020 Quant Question 26
- CAT 2020 Quant Question 27
- CAT 2020 Quant Question 28
- CAT 2020 Quant Question 29
- CAT 2020 Quant Question 30
- CAT 2020 Quant Question 31
- CAT 2020 Quant Question 32
- CAT 2020 Quant Question 33
- CAT 2020 Quant Question 34
- CAT 2020 Quant Question 35
- CAT 2020 Quant Question 36
- CAT 2020 Quant Question 37
- CAT 2020 Quant Question 38
- CAT 2020 Quant Question 39
- CAT 2020 Quant Question 40
- CAT 2020 Quant Question 41
- CAT 2020 Quant Question 42
- CAT 2020 Quant Question 43
- CAT 2020 Quant Question 44
- CAT 2020 Quant Question 45
- CAT 2020 Quant Question 46
- CAT 2020 Quant Question 47
- CAT 2020 Quant Question 48
- CAT 2020 Quant Question 49
- CAT 2020 Quant Question 50
- CAT 2020 Quant Question 51
- CAT 2020 Quant Question 52
- CAT 2020 Quant Question 53
- CAT 2020 Quant Question 54
- CAT 2020 Quant Question 55
- CAT 2020 Quant Question 56
- CAT 2020 Quant Question 57
- CAT 2020 Quant Question 58
- CAT 2020 Quant Question 59
- CAT 2020 Quant Question 60
- CAT 2020 Quant Question 61
- CAT 2020 Quant Question 62
- CAT 2020 Quant Question 63
- CAT 2020 Quant Question 64
- CAT 2020 Quant Question 65
- CAT 2020 Quant Question 66
- CAT 2020 Quant Question 67
- CAT 2020 Quant Question 68
- CAT 2020 Quant Question 69
- CAT 2020 Quant Question 70
- CAT 2020 Quant Question 71
- CAT 2020 Quant Question 72
- CAT 2020 Quant Question 73
- CAT 2020 Quant Question 74
- CAT 2020 Quant Question 75
- CAT 2020 Quant Question 76
- CAT 2020 Quant Question 77
- CAT 2020 Quant Question 78