I think the answer is going to be a
Answer:
She bought 24 Tangram puzzles
Step-by-step explanation:
Let the number of Tangram puzzles be t and the number of IQ puzzles be i
The sum of all the puzzles is 40;
i + t = 40 ••••••(i)
Cost of all Tangram puzzles at a cost of $4 per one will be;
4 * t = $4t
cost of all Iq puzzles at a cost of $2 per one is
2 * i = $2i
Sum
paid for all is $128
so;
4t + 2i = 128 •••••••(ii)
From equation i;
i = 40-t
Substitute into ii
4t + 2(40-t) = 128
4t + 80 - 2t = 128
2t = 128-80
2t = 48
t = 48/2
t = 24
