h$=4h²-10h If 3c$=90c, find all values of c.

x∆c=4x-5xc+10c If 4∆3b=10b, find b∆b.

a∇b=5a-3b+abc If 10∇10=1200, find 5∇6.

n people purchase a gift (g) for $l. m people purchase another gift (p) for $q. If n>m and l<q, find the difference in price between g and p.

F(x)=3x²-10x If F(2b)=100b, find all values of b.

How many integers between 0 and 999 contain a single digit that is a 7?

The probability of scoring 90 or above is .35 in a group of 11 students, find the probability that 10 or 11 score a 90 or above?

In a bag there are 6 blue marbles, 4 red marbles, 7 yellow marbles, and 3 white marbles. How many which should be added so p(white) becomes .34?

Alan has 11 friends and is selecting 5 to come on a trip with him. How many ways can this be done?