The toys are different; The boxes are identical
If none of the boxes is to remain empty, then we can pack the toys in one of the following ways
a. 2,2,1
b. 3,1,1
Case a. Number of ways of achieving the first option 2?2?1
Two toys out of the 5 can be selected in
5 ways. Another 2 out of the remaining 3 can be selected in
ways and the last toy can be selected in
way.
However, as the boxes are identical, the two different ways of selecting which box holds the first two toys and which one holds the second set of two toys will look the same. Hence, we need to divide the result by 2.
Therefore, total number of ways of achieving the 2?2?1 option is:
ways.
Case b. Number of ways of achieving the second option 3?1?1
Three toys out of the 5 can be selected in
ways. As the boxes are identical, the remaining two toys can go into the two identical looking boxes in only one way.
Therefore, total number of ways of getting the 3?1?1 option is
=10 ways.
Total ways in which the 5 toys can be packed in 3 identical boxes
=number of ways of achieving Case a + number of ways of achieving Case b
=15 + 10 = 25 ways
3739 + 164 x 27 = ?
? = 3739 + 4428 = 8167 ? 8200
190 - 24 = 166 166 - 21 = 145 145 - 18 = 127 [Here, 128 is placed instead of 127] 127 - 15 = 112 112 - 12 = 100 ... and so on.
Therefore, 128 is wrong.
There are 12 letters in the world 'civilization' of which four are i's and other are different letters.
? Total number of permutations = 12!/4!
But one word is civilization itself.
? Required number of rearrangements = 12!/4! - 1
We may choose 1 officer and 5 jawans or 2 officers and 4 jawans ......... or 4 officers and 2 jawans.
So Required answer = [4C1 x 8C5] + [4C2 x 8C4] + [4C3 x 8C3] + [4C4 x 8C2]
= 224 + 420 + 224 + 28 = 896.
Let ages of man and his son are 8k yr and k yr, respectively .
According to the question,
(8k + k)/2 = 27
? k = (27 x 2)/9 = 6
Hence, age of son after 6 yr = 6 + 6 = 12 yr
We know that, nPr = nCrr!
? nPr = 720nCr
? nCr.r! = 720nCr
? r! = 720
? r = 6
As per figure we can calculate the ration as below.
Number of supervisors / Number of labourers = (10 / 100) = 1/10
Total number of labourers = Total no. of supervisors × 10
= 15 × 10 = 150.
If the required fraction be N.
Then, (N x N) / (1/N) = 1826/27
? N3 = 512 / 27
? N = 8/3 = 22/3
Comments
There are no comments.Copyright ©CuriousTab. All rights reserved.