A group of 630 children is seated in rows for a group photo session. Each row contains three less children than the row in front of it. Which one of the following number of rows is not possible?
a. 6
b. 3
c. 4
d. 5
Arithmetic progression.
Each row has people as below
A, A+3,A+6 and so on.
Sum = n/2(2A+(n-1)d)
630 ×2 = n()
.. can't solve!
A bag contains 20 balls. 8 balls are green, 7 are white and 5 are red. What is the minimum number of balls that must be picked up from the bag blindfolded (without replacing any of it) to be assured of picking at least one ball of each colour?
a. 13 b. 11 c. 17 d. 16
16.
If we pick up 5 it can be only gree or all red or all white. But if we choose 6, then even if all 5 red balls are picked, we know that at least one ball will be gree or white.
If we pick up 8, we know that all 8 balls may be gree only
If we pick up 8 balls, which by our bad luck is all green, and then we keep picking up balls and by bad luck they can be all white balls till 15 balls. but 16th ball will 100% be of red color because all other balls have been picked up.
good questions. earlier when i saw this question, i thought it was pwrmutationr or probability. then i thought i will solve it on pen and paper, when i sat down, it was simpler!
A selection is to be made for one post of Principal and two posts of Vice-Principal. Amongst the six candidates called for the interview, only two are eligible for the post of Principal while they all are eligible for the post of Vice-Principal. The number of possible combinations of selectees is
a. 4 b. 12 c. 18 d. None of the above
Is it 6c2 * 2c1
Have forgotten the formula :P
@Nikita 2c1 for princi because 1 will be selected from 2 candidates.5c2 for VP because 1 person is already selected for princi,rest 2 would be selected from remaining 5 candidates
Which app do you use?
Notability or good notes?
Which ipad model do you have ?
Tell me more!
Do you make all notes in ipad. Is it tiring?
Do you use apple pencil 2?
Is that a font ???
Did you do it on iPad? What font do you use? What one do you use??
You will beat Anudeep in handwriting!
21. When the digits of two-digit numbers are reversed, the number increases by 27, the sum of such two-digit numbers
(a) 235
(b) 249
(c) 213
(d) 180
21. (B)
Hahaha... thanks. I wrote it on ipad. Not a font.
