1. **State the problem:** A mother bought 3 packs of Supligen and 4 packs of Orange juice for 13.40. If she had bought 4 packs of Supligen and 3 packs of Orange juice, the cost would have been 14.95. 2. **Write simultaneous equations:** Let $s$ be the cost per pack of Supligen and $j$ be the cost per pack of Orange juice. From the problem, we have: $$3s + 4j = 13.40$$ $$4s + 3j = 14.95$$ 3. **Solve the system:** Multiply the first equation by 3 and the second by 4 to eliminate $j$: $$9s + 12j = 40.20$$ $$16s + 12j = 59.80$$ 4. **Subtract the first from the second:** $$16s + 12j - (9s + 12j) = 59.80 - 40.20$$ $$7s = 19.60$$ 5. **Solve for $s$:** $$s = \frac{19.60}{7}$$ $$s = 2.80$$ 6. **Substitute $s=2.80$ into the first equation:** $$3(2.80) + 4j = 13.40$$ $$8.40 + 4j = 13.40$$ 7. **Isolate $j$:** $$4j = 13.40 - 8.40$$ $$4j = 5.00$$ 8. **Solve for $j$:** $$j = \frac{5.00}{4}$$ $$j = 1.25$$ **Final answers:** - Cost per pack of Supligen $s = 2.80$ - Cost per pack of Orange juice $j = 1.25$