Data Sufficiency

Source: Magoosh

Andres bought exactly two sorts of donuts, old-fashioned donuts and jelly donuts. If each old-fashioned donut costs $0.75 and each jelly donut costs $1.20, how many jelly donuts did Andres buy?

1) Andres bought a total of eight donuts
2) Andres spent exactly $7.35 on donuts

The OA is B

BTGmoderatorLU wrote: ↑

Sat Jul 31, 2021 1:00 pm

Source: Magoosh

Andres bought exactly two sorts of donuts, old-fashioned donuts and jelly donuts. If each old-fashioned donut costs $0.75 and each jelly donut costs $1.20, how many jelly donuts did Andres buy?

1) Andres bought a total of eight donuts
2) Andres spent exactly $7.35 on donuts

The OA is B

1) Andres bought a total of eight donuts.
\(O+J=8.\) Not sufficient. \(\Large{\color{red}\chi}\)

2) Andres spent exactly \(\$7.35\) on donuts.
\(0.75 \ast O + 1.2 \ast J = 7.35\)
\(75O + 120J = 735\)
\(5O + 8J = 49\)
\(O=5, J=3\) only one set of values satisfies this equation. \(\Large{\color{green}\checkmark}\)

Therefore, B