How many times greater is 6.45 than 0.01?

One card is dealt from a 52 card deck. find the probability that the dealt card is a 4 or a black 7

When you flip a biased coin the probability of getting a tail is 0.6. how many times would you expect to get tails if you flip the coin 320 times?

Bob paid $3 less than tim at a local pizza parlor. together they spent $7.80. how much did bob pay for pizza?