There are 4 boys and 12 students in total. It would be 4/12, but if it was to be simplified, it would be 1/3. The probability of a boy being selected is 1/3.
Answer:
As both the mean and standard deviation are in the desired ranges, the tool passes the technical control.
Step-by-step explanation:
Mean of the batch:
The mean of the batch is the sum of all values divided by the number of items. So
Mean in the desired interval.
Standard deviation:
Square root of the sum of the difference squared between each term and the mean, divided by the number of items. So
As both the mean and standard deviation are in the desired ranges, the tool passes the technical control.
Answer:
(a) How many are there to select 2 pairs of gloves?
10 ways
(b) How many ways are there to select 4 gloves out of the 10 such that 2 of the 4 make a pair. (a pair consists of any right glove and left glove.)
130 ways
Step-by-step explanation:
We solve the above questions using Combination
Combination = C(n, r) = nCr
= n!/n! ×(n - r)!
(a) How many are there to select 2 pairs of gloves?
We have 5 pairs of gloves. Therefore, the number of ways to select 2 gloves =5C2
= 5!/2! × (5 - 2)!
= 5!/2! × 3!
= 5 × 4 × 3 × 2 × 1/(2 × 1) × (3 × 2 × 1)!
= 10 ways.
(b) How many ways are there to select 4 gloves out of the 10 such that 2 of the 4 make a pair. (a pair consists of any right glove and left glove.)
We are told to select 4 gloves out of the 10 gloves = 10C4
We have 5 pairs, we need to make sure that two out of the selected 4 make a pair = 5 × 2⁴
= 80
Hence,
10C4 - 5C4
= [10!/4! × (10 - 4)!] - 80
= 210 - 80
= 130 ways
Let the speed of walking of James = x mile/hour
speed of jogging = 2x mile/hour
9/2x + 1.5/x = 2
or, (9 + 3)/2x = 2
or, 12 = 4x
or, x = 3
Average speed of walking = 3 mile/hour
Average speed of jogging = 2 * 3 = 6 mile/hour
