CTET Solved Paper - CTET September 2015
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112. The smallest value of y in the number 9y8071 so that it is divisible by 11 is
- Option : C
- Explanation : (C) We can solve this by using the divisibility rule of 11.
It states that when the sum of digits at odd and even places are equal or differ by a number divisible by 11, then the number is also divisible by 11.
For, 9y8071
Sum of digits at odd places = 9 + 8 + 7 = 24
Sum of digits at even places = y + 0 + 1 = y + 1
⇒ 24 - (y + 1) = 23 - y
∴ To make this number divisible by 11, we have to put the value of y as 1.
113. (14.96 × 1010) - (3.84 × 108) is expressed in standard form as
- Option : B
- Explanation : (B) (14.96) × 1010 - (3.84) × 108
= (1496) × 108 - (3.84) × 108
= (1496 - 3.84) × 108
= 1492.16 × 108
= 1.49216 × 1011
114. The sum of mean, mode and median of the data 6, 3, 9, 5, 1, 2, 3, 6, 5, 1, 3 is
- Option : C
- Explanation : (C) 6, 3, 9, 5, 1, 2, 3, 6, 5, 1, 3
Arranging them in ascending order, we get
1, 1, 2, 3, 3, 3, 5, 5, 6, 6, 9
Mode of the data = 3, Median of the data = 3
∴ Sum of mean, mode, median = 4+3+3 = 10
- Option : A
- Explanation : (A) Total number of outcomes = 12
Favourable number of outcomes (to be a prime number) = 4 (i.e 5, 7, 11, 13)
