From the 8th to the 13th there are five numbers, and the difference between the 8th and the 13th is 20-12.5=7.5, so the difference between two neighboring number is 7.5÷5=1.5
from the 13th and the 25th there are 12 numbers, so the total difference is 12*1.5=18
so the 25th term is 20+18=38
3. He can divide 231 by 12 or he can see which number he can multiply by 12 to get 231.
4. 98 cubic meters
A₁ = 1; r=1.5
a₉ = a₁ * r⁸ = 1 * 1.5⁸ ≈ 25.63
Answer: c. 25.63
Answer = $39.78
100-20 =80
100-25=75
Multiply 60 x .80 to get $48
Then multiply 48 x .75 to get $36
Sales tax %10.5 = move decimal two places to left .105
Now multiply 36 x .105 =3.78
$3.78 equals your sales tax
Finally add $3.78+$36= $39.78
The answer would be 101/20
