SSC CPO Paper I 23 Nov 2020 Shift 3 – Question Paper

Concept: Replace each letter by its operation, then use BODMAS (brackets, division/multiplication, addition/subtraction).

1. Expression becomes $74+(31\times 2)\times 2-(68-4)÷(4\times 2)$.
2. Brackets: $31\times 2=62$, $68-4=64$, $4\times 2=8$.
3. $74+62\times 2-64÷8=74+124-8$.
4. $=190$.

Trick: Solve brackets first, then $÷$ and $\times$, last $+$ and $-$.

Answer: (B) 190

Concept: Chemical symbols are one or two letters, usually from the English or Latin name of the element.

1. Arsenic (atomic number 33) is a metalloid of Group 15; its symbol is As.
2. Ac = Actinium, Ar = Argon; 'An' is not the symbol of any element.

Yaad rakhein: Ar-se-nic → first two letters As; do not confuse with Ar (Argon).

Answer: (C) As

Concept: Area of a square $=\frac{d^2}{2}$, so area $\propto d^2$ and $d\propto \sqrt{\text{Area}}$.

1. New area $=100\%-19\%=81\%$ of old area.
2. New diagonal $=\sqrt{0.81}=0.9$ times old diagonal.
3. Decrease $=1-0.9=0.1=10\%$.

Trick: Area factor $0.81=(0.9{)}^2$, so every length (side, diagonal) falls by $10\%$.

Answer: (A) $10\%$

Concept: To show that something is sufficient for a purpose we use adjective/adverb + enough + to-infinitive, not 'so much to'.

1. 'So much' needs a result clause with that (so much that …) or 'as to'; 'so much to make' is incorrect.
2. The idea is sufficiency: earning sufficient money to meet expenses.
3. Correct sentence: Do you earn enough to make both ends meet?
4. 'Do you earn', 'make both', 'ends meet' are correct (idiom: make both ends meet = manage expenses).

Trick: Sufficient for a purpose → enough to; result → so … that.

Answer: (D) so much to