Richard packed some marbles into 12 small packets and 20 large packets.
Each large packet contained 8 more marbles than each small packet. 1/4 of the
total number of marbles was packed into small packets.
(a) How many marbles did Richard pack into large packets?
(b) How many marbles did Richard have?
Number in each small packet==S
Number in each large packet==L
L ==S + 8
12S + 20[S +8] ==32S + 160 - total of all marbles.
1/4 * [32S + 160] =12S, solve for S
S ==10 - number of marbles in each small packet
L ==10 + 8==18 - number of marbles in each large packet.
(a) 18 marbles x 20 large packets ==360 marbles.
(b) 360 + [10 * 12]==360 + 120 ==480 marbles altogether.