The ratio of the present age of mother and daughter is 3:1. Six years ago the ratio of their age was 6 : 1. Find their present a
1 answer:
Answer:
30 and 10
Step-by-step explanation:
Given ratio of age = 3 : 1 = 3x : x ( x is a multiplier )
Six years ago their age ratio was
3x - 6 : x - 6 = 6 : 1 ← express in fractional form
=
( cross- multiply )
6(x - 6) =3 x - 6
6x - 36 = 3x - 6 ( subtract 3x from both sides )
3x - 36 = - 6 ( add 36 to both sides )
3x = 30 ( divide both sides by 3 )
x = 10
Thus their present ages are
mother = 3x = 3 × 10 = 30
daughter = x = 10
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Answer:
= 1+2n and 63
Step-by-step explanation:
the question belongs to arithmetic sequence and can be determined by the formula
= a1 + d (n-1)
Let " " represents the number of band members in the nth row
and 'd' represents the common difference.( as stated each row has 2 more band members than the row before it)
therefore, d=2
'a1' represents first row that has three members. So, a1 = 3
->Rule for nth term will be:
= 3 + 2(n-1)
= 3 + 2n -2
= 1+2n
-> In order to find total number of band members ''
Let represent total number in n rows
We'll use the formula, i.e = n/1 (
+
)
where, n is the number of terms, is the first term and
is the last term
So,
n=7
= 1 + 2(7)= 15
=> = 7/2 (3 + 15)
= 63
The total number of band members are 63