Male student: 40/100 = 2/5
graduate: 520/2106 = 65/252
2/5 + 65/252
= 829/1260 ( this is the probability)
Answer: N=800/5
N=160
He needs to save $160 every week to get $800 in 5 weeks
hope this helps.
The average is found by adding the numbers and dividing by 2.
Since the average is 17, the total of the two numbers must equal 17 x 2 = 34.
One number is given as 11, so subtract 11 from 34:
34 - 11 = 23
The other number is 23.
Too check: add 11 and 23 and then divide by 2:
11 + 23 = 34
34/2 = 17.