Question

Need help on to algebra questions!!!

14. Fifteen coins consisting of nickels, dimes, and quarters were collected from a newspaper vending machine. The total value of the coins is $1.95, and there are 4 more dimes than quarters. Find the number of each type of coin.

A. 2 nickels; 9 dimes; 5 quarters

B. 5 nickels; 7 dimes; 3 quarters

C. 7 nickels; 6 dimes; 2 quarters

D. 3 nickels; 8 dimes; 4 quarters

17. Which relation is not a function?

A. {(–7,2), (3,11), (0,11), (13,11)}

B. {(7, 11), (11, 13), (–7, 13), (13, 11)}

C. {(7,7), (11, 11), (13, 13), (0,0)}

D. {(7, 11), (0,5), (11, 7), (7,13)}

Answer 1

A

Explanation:

14 is A because its dividing and operating

Answer 2

D, D

Explanation:

Nickels are $0.05, Dimes are $0.10 and quarters are $0.25

Simply work out the options and see which one gives you $1.95

A) By observation, we see that this combination has 16 coins, but the question says only 15 coins. Hence we can remove this as an option.

B) 5($0.05) + 7($0.10) + 3($0.25) = $1.70 ≠ $1.95 (wrong)

C) 7($0.05) + 6($0.10) + 2($0.25) = $1.45 ≠ $1.95 (wrong)

D) 3($0.05) + 8($0.10) + 4($0.25) = $1.95 (Correct)

FOr next question, D is not a function because if you observe the values in D, an input of 7 should give 11 i.e (7,11), but there is another option where 7 gives an output of 13 i.e (7,13).

Because for a function to be valid, one input cannot give 2 different outputs, D is not a function.