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# In an arithmetic sequence with 25 terms, if the first term is 60 and last term i...

### Question

In an arithmetic sequence with 25 terms, if the first term is 60 and last term is -12 the common difference is

### Options

A) 3

B) 2

C) -3

D) -2

The correct answer is C.

### Explanation:

$$L=a+[n-1]d; L=-12, a=60, n=25$$
$$-12=60+[25-1]d$$
$$-12=60+[24d]$$
$$-12-60=24d$$
$$24d =-72$$
$$d=-\cfrac{72}{24}$$
$$d=-3$$

Explanation provided by Ayoola Favour

## Dicussion (1)

• $$L=a+[n-1]d; L=-12, a=60, n=25$$
$$-12=60+[25-1]d$$
$$-12=60+[24d]$$
$$-12-60=24d$$
$$24d =-72$$
$$d=-\cfrac{72}{24}$$
$$d=-3$$