I did 21000-5000 =16000
that is the difference between the least and greatest value right?
I just calculated which no is divided by 8 = integer. Is my logic incorrect?
Cud someone pls solve this one
Just find how many 4 can u make in 20!
Is answer 9?
I tried to brute force it quickly
Yes its 9 but I got 8
20! = 1 \times 2 \times 3 ....\times20
Now, if you only check for 4 then you will miss 2’s and the fact that 2x2 = 4.
So, a full-proof solution will be to find the highest power of 2 that divide 20! and then divide that by 1/2 to get no. 4
\frac{20}{2} =10 \\
\frac{10}{2} =5 \\
\frac{5}{2} =2 \\
\frac{2}{2} =1 \\
we’re ignore the remainder in here!
Now, just add the quotients = 10+5+2+1 = 18. So, highest power of 2 that can divide 20! is 18, divide that by half to get number of 4’s = 18/2 = 9
Yup got it 
Is my logic correct for the 2nd question?
I don’t understand your explanation.
How wud u solve the problem. what wud be the approach
This looks like 4 to me.
I started off thinking about the extremes: what if we have 8 students? Then there’s only one distinct group. Same if you have only 1 student in each group. Also see In how many different ways can a group of 8 people be divide : Problem Solving (PS)
Yes its 4
I just calculated which no is divided by 8 = integer.
I was unsure if this approach was right