1999 CEMC Gauss (Grade 7) Problems/Problem 3

Problem

Susan wants to place $35.5$ kg of sugar in small bags. If each bag holds $0.5$ kg, how many bags are needed?

$\text{(A)}\ 36 \qquad \text{(B)}\ 18 \qquad \text{(C)}\ 53 \qquad \text{(D)}\ 70 \qquad \text{(E)}\ 71$

Let $b$ be the number of bags needed. Since each bag has $0.5$ kg, and the total mass must be $35.5$ kg, we have:

$0.5b = 35.5$

Dividing both sides by $0.5$ gives:

$b = \boxed{\textbf{(E) }71}$

~anabel.disher

We can see that multiplying by $0.5$ results in the value being halved.

Since $35$ is half of $70$ , but $35.5$ is more than $35$ , we can see the answer must be more than $70$ .

The only answer choice that is more than $70$ is $\boxed{\textbf{(E) }71}$

~anabel.disher