Answer:
He should have to spell at least 36 of these words correctly.
Step-by-step explanation:
40 words.
He must spell at least 90% of those words correctly.
At least how many words should he have to spell correctly to get the prize?
90% of 40. So
0.9*40 = 4*9 = 36
He should have to spell at least 36 of these words correctly.
1/3<3/3
or 1/3<1
so 1/3 is close to 1 than 2 and 3
5 and 20 because if the perimeter is 50 the width is 5 and 5 x 4 is 20
Answer:
24. 40 minutes approximately
25. 8 days
Step-by-step explanation:
24. 40 minutes
Anna: 1 hour
Peter: 3 hours
Maria: 6 hours
A way to solve this kind of question is to think about how much they can perform given the same amount of time.
Anna: 1 hour x 6: 6 hours (In 6 hours Anna can clean 6 houses)
Peter: 3 hours x 2 6 hours (In 6 hours Peter can clean 2 houses)
Maria: 6 hours x 1: 6 hours (In 6 hours Peter can clean 1 house)
Working together they can clean the house 9 times faster.
It is 0.66 hours, or approximately 40 minutes
25. 8 days
It climbs 3 feet up but then it falls 2 feet down while sleeping during
the night. So the snail actually climbs 1 foot every day. It happens in the first 7 days. On the 8th day it goes out before sleep.
C = the square root of a^2 + b^2
AC = the sqrt of AB^2 + BC^2
AC = sqrt of 6^2 + 10^2
AC = 11.66
