Question

Allen started to save money from his daily allowance. In the first week he saved $5.8 and every next week $3.6 more than the previous week. How much money did he save in 4 weeks?

Answer 1

Answer: $16.60

Explanation:

5.80+ 3.60= 9.40+ 3.60= 13.00+ 3.60= 16.60

So after 4 weeks he earned $16.60

Answer 2

$44.8.

Explanation:

Let a = first term = $5.8

d = common difference = $3.6

n = number of terms = 4

Using the sum of terms

Sn = n/2((2a + (n - 1)d))

Sn = 4/2((2(5.8) + (4 - 1)3.6))

= 2(11.6 + 10.8)

= 2(22.4)

= 44.8

In 4 weeks, Allen would have saved $44.8.