John has two pumps to inflate his raft. One pump can fill the raft 1.25 times as fast as the second pump. When John uses both pumps, the raft is inflated in 5 hours. How long would it take John to inflate the raft if he only used the slower pump?

1.6hours

Step-by-step explanation:

let let the slower pump take x hours

then the faster pump will take 1.25x hours to pump the raft

The combined work rate is 5 hours

The expression for the combined work rate is

1/x+1/1.25x= 1/5

solve for x we have

1.25+x/1.25x= 1/5

cross multiply we have

5(1.25+x)= 1.25x

6.25+5x=1.25x

collect like terms

6.25+5x-1.25x=0

6.25+3.75x=0

3.75x=-6.25

divide both sides by 3.75

x=-6.25/3.75

x=-1.6 hours

x= 1.6hours

answer: i think the answer is etheir c or d but i don't know which one but have a good day!

step-by-step explanation:

3.4 pizzas

step-by-step explanation:

given is a scatter plot showing number of pizzas sold during weeks for different issues of coupon

y represents number of pizzas sold and x number of coupons issued

y is marked verticaly and x horizontally

the trend line is given as

y =3.4x+43

this says that even when no coupon is issued pizzas sold will be 43

and rate of change of pizza sold for 1 unit of coupon = slope = 3.4

i.e. when x increases by 1 unit y increases by 3.4 units

hence for each additional coupon issued 3.4 pizzas more will be sold