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pelz tell me all the answer of the question one question not allowed
Answers
Answer:
1)nth term= a+(n-1)d
6 term = -12+(6-1)d
8=-12+(5)d
20=5d
4=d. (1)
we know that
s nth =1/2 × n × (1st term + last term)
120=n/2 (2 (-12)+(n-1)d)
120=n/2 (-24+4n-4)
120=n (-12+2n-2)
120=-12n+2n^2-2n
120=2n^2-14n
60=n^2-7n
n^2-7n-60=0
n^2-12n+5n-60=0
n (n-12)+5 (n-12)
n+5 and n-12
n=-5 and 12
terms cannot be negative
therefore terms are 12.
2)The 1st two digit no. which are divisibe by 6 is 12 and the last two digit no. is 96.
LET a=12, d=6 and =96
Now,
=a+(n-1)d
96=12+(n-1)6
84=(n-1)6
n-1=14
n=14+1
n=15
Hence total no. of two digit no. divisible by 6 is 15
3)Sn = (3N²-4N)------------(1)
Replacing n by (n-1) in equation (1) , we get
Sn-1 = 3(N-1)² - 4 × (N-1)
=> Sn-1 = 3(N²-2N+1) - 4N+4
=> Sn-1 = 3N²-6N+3-4N+4
=> Sn-1 = 3N²-10N+7
Therefore,
Tn = (Sn-Sn-1) => (3N²-4N)-(3N²-10N+7)
Tn = 3N²-4N-3N²+10N-7 = (6N-7).
Therefore,
Nth term , Tn = (6N-7)
4) A4+a8=24
a+3d+a+7d=24
2a+10d=24. .........1
a6+a10=34
a+5d+a+9d=34
2a+14d=34. .,.......2
Subtracting 2 from 1
2a+14d=34
2a+10d=24
- - -
4d=10
d=4/10or 2/5
Put d= 2/5 in 1
2a+10×2/5=24
2a+4=24
2a=24-4
2a=20
a=10
Answer:
given what portion of saree can zainab in 1 hour if it requires 7 hours to paint the whole .
now we need to find the portion of the saree that is to be painted in one hour, if the whole portion can be painted in 7 hours.
so we can write it as
7 hours is required to paint 1 whole portion.
so in 1 hour the saree portion that can be painted will be 1/7 th part.
so 1/7 th part of zianab saree will be painted in 1 hr.