Step-by-step explanation:
let X = speed of slow bicycle rider
2x=speed of fast bicycle rider
3(x+2x)=72
X=8mph(slowest bicycle rider)
2x=16mph(fastest bicycle rider)
There are 9 numbers less than 10. 1,2,3,4,5,6,7,8,9
And there are 2 multiples of 15. 15,30
There are 11 of the 40 cards that are either less than 10 or multiples of 15, so the answer is B
