Correct Answer: 2 and 8

Solution : Given:
(240 ÷ 2 + 5) × 8 + 15 × 8 = 100

Interchange the numbers according to the given options.
First option: 2 and 8
(240 ÷ 8 + 5) × 2 + 15 × 2 = 100
Solving the L.H.S. of the equation –
= (30 + 5) × 2 + 15 × 2
= 35 × 2 + 15 × 2
= 70 + 30
= 100 = 100 (L.H.S. = R.H.S.)
Second option: 100 and 240
(100 ÷ 2 + 5) × 8 + 15 × 8 = 240
Solving the L.H.S. of the equation –
= (50 + 5) × 8 + 15 × 8
= 55 × 8 + 15 × 8
= 440 + 120
= 560 ≠ 240
Third option: 5 and 8
(240 ÷ 2 + 8) × 5 + 15 × 5 = 100
Solving the L.H.S. of the equation –
= (128) × 5 + 15 × 5
= 640 + 75
= 715 ≠ 100
Fourth option: 15 and 5
(240 ÷ 2 + 15) × 8 + 5 × 8 = 100
Solving the L.H.S. of the equation –
= (120 + 15) × 8 + 5 × 8
= 135 × 8 + 5 × 8
= 1080 + 40
= 1120 ≠ 100

So, the required numbers to correct the equation are 2 and 8. Hence, the first option is correct.