Rationale: 21-12 < no of hrs < 21-6
9< no of hrs < 14.
The answer: (D)
Question: Resident of town X participated in a survey to determine the number of hours per week each resident spent watching television. The distribution of the results of the survey had a mean of 21 hours and std deviation of 7 hrs. The number of hours that pat, a resident of town X, watched television last week was between 1 and 2 standard deviation below the mean. Which of the following could be the number of hours that Pat watched television last week?
Options:
(A) 30
(B) 20
(C) 18
(D) 12
(E) 6

Reasoning: There are 4 ways to roll a nine: 3 and 6, 6 and 3, 4 and 5, 5 and 4 with two six-sided dice. There are 6 times 6 = 36 ways to roll two dice. The probability of rolling a 9 is thus 4/36 = 1/9.
Ans: (B)
Question: What is the probability of rolling a nine with two, fair, six-sided dice?
Options:
(A) 1/6
(B) 1/9
(C) 2/13
(D) 1/12
(E) 5/36

Rationale: 137-731 and 276-672 similarly 435-534
The answer: (A)
Question: 137+276=435 how much is 731+672?
Options:
(A) 534
(B) 1403
(C) 1623
(D) 1513
(E) 1613

Reasoning: Speed = 120*(5/18) m/sec = 200/6 m/sec
Length of Train (Distance) = Speed * Time
(200/6) * 9 = 300 meter
Ans: (E)
Question: A train running at the speed of 120 km/hr crosses a pole in 9 seconds. Find the length of the train.
Options:
(A) 100 meter
(B) 150 meter
(C) 200 meter
(D) 250 meter
(E) 300 meter

Rationale: 520 = 26 * 20 = 2 * 13 * 22 * 5 = 23 * 13 * 5
Required smallest number = 2 * 13 * 5 = 130
130 is the smallest number which should be multiplied with 520 to make it a perfect squar
The answer: (E)
Question: Find the smallest number which should be multiplied with 520 to make it a perfect square.
Options:
(A) 30
(B) 120
(C) 55
(D) 35
(E) None of these

Rationale: Speed = 90*(5/18) m/sec = 25 m/sec
Length of Train (Distance) = Speed * Time
25 *10 = 250 meter
The answer: (C)

Question: A train running at the speed of 90 km/hr crosses a pole in 10 seconds. Find the length of the train.
Options:
(A) 150
(B) 180
(C) 250
(D) 200
(E) 225