Find the 60th term of the AP 8, 10,12, ..., if it has a total of 60 terms and hence find the sum of its last 10 terms.
The given AP is 8, 10, 12, ....
So,
First term =a = 8
Common difference = d = 10-8 =2
We know that nth term of an AP, an = a + (n - 1)
60th term of the given AP = a60 = 8 +( 60-1) x 2 = 8 + 59 x 2 = 8 + 118 = 126
Therefore, the 60th term of the given AP is 126
It is given that the AP has a total of 60 terms. So, in order to find sum of last n terms. we take
First term, A = 126
Common difference, D = -2
Now,
Construct a ΔABC in which AB = 6 cm, ∠A = 30o and ∠B = 60o. Construct another ΔAB'C' similar to ΔABC with base AB' = 8 cm
Find the values of k so that the area of the triangle with vertices (1,-1), (-4, 2k) and (-k, 5) is 24 sq. units