Answer: Correct two digit number= 24
Step-by-step explanation:
Let
x= tens digit (wrong one)
and y= zeroes digit
and z= tens digit (right one)
Now according to the statement,
(10x+y)² - (10z+y)² = 2340
Simplifying this we get
(x-z)(5x+y+5z)= 117= 1 * 3 * 3 * 13
So it could either be
x-z=1 or x-z=3
If we take the x-z=1
then 5x+y+5z=117
which is not possible as maximum value we can get from this is 99.
This leaves us with x-z=3
so 5x+y+5z= 39
Put x=3+z
We get,
y+10z= 24
Now as y and z both are single digits so the only possible numbers to fit these are y=4 and z=2.
Put z=2 in x=3+z , we get x=5
So the numbers become 10x+y= 54
and 10z+y= 24
Their sum is 54+24=78
Check
54²-24²= 2340 so it is correct.
Answer:
720
Step-by-step explanation:
Since we are choosing a subset of 3 people from a set of 10 people, and arranging the 3 people according to relative strength, the answer can be obtained by computing P(10,3).
P(10,3)=10! / (10-3)!
= 10!/7!
Rewrite 10
! as
10 * 9 * 8 * 7
! / 7!
Cancel the common factor of 7
! and divide (
10 * 9 * 8
) by 1
10 * 9 * 8 = 720
Hope this answer helps you! If it did, please mark it as the brainiest! I would really appreciate it! :)
