Question : Directions: By interchanging the given two signs and numbers which of the following equations will be correct?
× and +, 6 and 4
Option 1: 3 × 9 – 4 ÷ 2 + 6 = 8
Option 2: 8 × 6 + 4 ÷ 2 – 5 = –5
Option 3: 8 – 3 × 6 + 4 ÷ 1 = 18
Option 4: 7 × 6 – 4 + 9 ÷ 3 = –7
Correct Answer: 7 × 6 – 4 + 9 ÷ 3 = –7
Solution :
Given:
× and +, 6 and 4
Let's check the given options –
First option:
3 × 9 – 4 ÷ 2 + 6 = 8
On interchanging the signs and numbers, we get –
3 + 9 – 6 ÷ 2 × 4 = 8
Solving the L.H.S. of the equation –
= 3 + 9 – 6 ÷ 2 × 4
= 3 + 9 – 3 × 4
= 3 + 9 – 12
= 12 – 12
= 0 ≠ 8
Second option:
8 × 6 + 4 ÷ 2 – 5 = –5
On interchanging the signs and numbers, we get –
8 + 4 × 6 ÷ 2 – 5 = –5
Solving the L.H.S. of the equation –
= 8 + 4 × 6 ÷ 2 – 5
= 8 + 4 × 3 – 5
= 8 + 12 – 5
= 20 – 5
= 15 ≠ –5
Third option:
8 – 3 × 6 + 4 ÷ 1 = 18
On interchanging the signs and numbers, we get –
8 – 3 + 4 × 6 ÷ 1 = 18
Solving the L.H.S. of the equation –
= 8 – 3 + 4 × 6 ÷ 1
= 8 – 3 + 4 × 6
= 8 – 3 + 24
= 32 – 3
= 29 ≠ 18
Fourth option:
7 × 6 – 4 + 9 ÷ 3 = –7
On interchanging the signs and numbers, we get –
7 + 4 – 6 × 9 ÷ 3 = –7
Solving the L.H.S. of the equation –
= 7 + 4 – 6 × 9 ÷ 3
= 7 + 4 – 6 × 3
= 7 + 4 – 18
= 11 – 18
= –7
So, from the above, only the fourth option satisfies the given equation. Hence, the fourth option is correct.
SSC CGL Complete Guide
Candidates can download this ebook to know all about SSC CGL.