7/100 = 0.07
0.07 * 12.5 = 0.88
20/100 = 0.2
0.2 * 12.5 = 2.5
2.5 + 0.88 = 3.38
3.38 + 12.50 = 15.88
You spend a total of $15.88.
Answer:
The length of the pendulum is 14.13 meters.
Step-by-step explanation:
The length of a pendulum is given by the formula,
, where T is the times period and L is the length of the pendulum.
Now, given that T = 2.4π seconds.
So, from the above equation, we get,

⇒ 
⇒
{We have the value of g as 9.81 m/sec²}
⇒ L = 1.44 × 9.81 = 14.13 meters. (Approx.)
Therefore, the length of the pendulum is 14.13 meters. (Answer)