Use proportions and use letters for unknown measurements
Answer:
21 boxes of books
Step-by-step explanation:
guy= 140 lbs
each box= 40lbs elevator can only weigh up to 1010
i took 1010- 140 and got 870lbs left for the books
then i took 870 divided by 40 (to see how many boxes of books can be put on the elevator) and got 21.75
so 21 boxes could go on the elevator at a time
Answer:

Step-by-step explanation:
We can apply Pythagoras' Theorem.

Answer:3100 with 9%
Step-by-step explanation:
Answer:
Osvoldo did not meet his goal
Step-by-step explanation:
To know the percentage of carbohydrates that Osvoldo ate from grains with respect to the total, we simply have to divide the amount of carbohydrates he got with the grains by the total
55 / 220 = 0.25
then to express it as a percentage this number has to be multiplied by 100
0.25 * 100 = 25%
Osvoldo wanted to reach 30% and only got 25%
25% < 30%