Question : Directions: Select the correct combination of mathematical signs to sequentially replace the * signs and to balance the given equation.
321 * 3 * 236 * 5 * 248 * 4 * 20 = 384

Option 1: +, –, ×, +, ÷, ×

Option 2: –, +, ×, –, ÷, +

Option 3: ÷, +, –, ×, +, –

Option 4: ×, +, –, ÷, +, –

Correct Answer: +, –, ×, +, ÷, ×

Solution : Given:
321 * 3 * 236 * 5 * 248 * 4 * 20 = 384

Let's check the given options –
First option: +, –, ×, +, ÷, ×
⇒ 321 + 3 – 236 × 5 + 248 ÷ 4 × 20 = 384
Solving the L.H.S. of the equation –
= 321 + 3 – 236 × 5 + 62 × 20
= 321 + 3 – 1180 + 1240
= 1564 – 1180
= 384 = R.H.S.
Second option: –, +, ×, –, ÷, +
⇒ 321 – 3 + 236 × 5 – 248 ÷ 4 + 20 = 384
Solving the L.H.S. of the equation –
= 321 – 3 + 236 × 5 – 62 + 20
= 321 – 3 + 1180 – 42
= 1501 – 3 – 42
= 1456 ≠ 384
Third option: ÷, +, –, ×, +, –
⇒ 321 ÷ 3 + 236 – 5 × 248 + 4 – 20 = 384
Solving the L.H.S. of the equation –
= 107 + 236 – 5 × 248 + 4 – 20
= 107 + 236 – 1240 + 4 – 20
= 347 – 1260
= –913 ≠ 384
Fourth option: ×, +, –, ÷, +, –
⇒ 321 × 3 + 236 – 5 ÷ 248 + 4 – 20 = 384
Solving the L.H.S. of the equation –
= 321 × 3 + 236 – 5 ÷ 248 + 4 – 20
= 321 × 3 + 236 – 0.0202 + 4 – 20
= 963 + 236 – 0.0202 + 4 – 20
= 1203 – 20.0202
= 1182.9798 ≠ 384

So, only the first option satisfies the given equation. Hence, the first option is correct.