Answer:
66
Step-by-step explanation:
Use the formula for the mean of a set of numbers:
sum of the numbers
average = --------------------------------
count of numbers
Here we know that the average mark was 68, so we can write:
75 + 62 + 84 + 53 + x
average = 68 = ----------------------------------
5
or 274 + x
68 = -------------------
5
Solving for x, we multiply both sides by 5: 340 = 274 + x.
Subtracting 274 from both sides effectively isolates x:
340 = 274 + x
- 274 -274
------------------------
66 = x
The fifth student's mark was 66.
Answer:
$28
Step-by-step explanation:
First to solve this get the original amount before his parents gave him $6
20-6=14
So he had $14 after spending it at the batting cages.
It is stated he spent half of his money there so multiply 14 by 2
14 x 2=28
So he has a weekly allowance of $28
10 move the decimal point over 3 spots
For 1. The bike is going 24 miles in 3 hours. To figure out how many miles it went in 1 hour you divide 24/3 which is 8 miles. If the bike went 8 miles per hour then you may now multiply it by 10 to find the total mileage in 10 hours. 10x8=80
Dividing fractions is equivalent to taking the reciprocal of the second and multiplying them. In this case, we have 1/2*8/5=8/10=4/5.
