In a garden bed , there are 23 rose plants in the first row, 21 in the second row, 19 in the third row and so on. thre are 5 plants in the last row .how many rows are there of rose plants? also find the total number of rose plants in the garden

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I think, there are 10 rows and 140 roses.
am I right?
yup....

Answers

  • Brainly User
2014-02-26T12:46:59+05:30
Here a=23 ; d= -2 and an=5
an = a + (n-1)d
-->5 = 23 + (n-1)-2-->5 = 23 +2 -2n
-->5 = 25 -2n
--> -2n = -20
-->n=10
Sn = n/2(a + an)
--> 10/2(23 + 5)
-->5 X 28=140
-->There are 140 roses on the flower bed..
Hope it Helps...Cheers..!!
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