Answer:
Step-by-step explanation:
Greatest multiplier of 4 that is less than 21 is 5 (4 x 5 = 20)
Put the remaining number as the numerator (21 - 20 = 1)
Step-by-step explanation:
2x-y=8
x+y=20
------------
3x=28
×=28÷3=9.3
so
9.3+y=20
y=20-9.3
y=20.7
Answer:
x = 115 - p
Step-by-step explanation:
generally in algebra you will use the letter "x" to represent a value you do not know, so it wants an algebraic expression for "p subtracted from 115", this can be rewritten as 115 - p. So the unknown value "x" is equal to 115 - p.
Answer:
210
Step-by-step explanation:
Here comes the problem from Combination.
We are being asked to find the number of ways out in which 3 students may sit on 7 seats in a row. Please see that in this case the even can not be repeated.
Let us start with the student one. For him all the 7 seats are available to sit. Hence number of ways for him to sit = 7
Let us see the student second. For him there are only 6 seats available to sit as one seat has already been occupied. Hence number of ways for him to sit = 6
Let us see the student third. For him there are only 5 seats available to sit as two seat has already been occupied. Hence number of ways for him to sit = 5
Hence the total number of ways for three students to be seated will be
7 x 6 x 5
=210
