Answer:
225
Step-by-step explanation:
Using the basic components of summation ∑
∑n = n(n + 1) and ∑1 = n
Thus
∑ (2n - 1) ← for n = 1 to 15
= ∑2n - ∑1
= 2∑n - ∑1
= 2 ( n(n + 1)) - n
= n(n + 1) - n ← Evaluate for n = 15 ( the upper value )
= 15 × 16 - 15
= 240 - 15
= 225
Answer:
15 bags
Step-by-step explanation:
She can fill 5 bags per each pound (because there are 5 per pound)
Since there are 3 pounds, and , again, each pound can fill 5 bags, she will need 15 bags.
Another way too look at it is to ask how many 1/5ths are in 3 pounds. To find this answer mathematically:
3 ÷ 1/5 = 15 because when we divide by a fraction, we need to flip it and then multiply (so 3 ÷ 1/5 is actually 3×5)
