mensuration Model Questions & Answers, Practice Test for ssc chsl tier 1 2024

Answer: (b)

Area left after laying black tiles

= [(20 – 4) × (10 – 4)] sq. ft. = 96 sq. ft.

Area under white tiles = $(1/3 × 96)$ sq.ft = 32 sq. ft.

Area under blue tiles = (96 – 32)sq.ft = 64 sq.ft.

Number of blue tiles = ${64}/{(2 × 2)}$ = 16

Answer: (b)

In right triangle ABC,

AC = $√{(AB)^2 + (BC)^2} = √{(40)^2 + (9)^2}$ = 41 cm

In ΔACD, AC = 41 cm, AD = 15 cm, CD = 28 cm

Area of ΔACD = $√{S(S - a)(S - b)(S - c)}$

Where S = ${a + b + c}/2 = {15 + 28 + 41}/2$ = 42 cm

∴ Area of ΔACD = $√{42(42 - 41)(42 - 28)(42 - 15)}$

= $√{42 × 1 × 14 × 27} = 2 × 3 × 3 × 7 = 126 cm^2$ .

Answer: (a)

Length of wire = 36 cm

∴ Perimeter of semi-circle = πr + 2r

⇒ 36 = r$({22}/7 + 2)$

⇒ r = ${36 × 7}/{36}$ = 7 cm

∴ Radius of semi-circle = 7 cm

Answer: (b)

Let $l_1 , l_2 , l_3$ and $l_4$ be your straight lines and t be a transversal.

∠1 = ∠3

∠2 = ∠4 [alternate angles]

Similarly angles formed by

$l_2 , l_3$ and $l_4$ are also equal in same way as $l_1$ corresponding angles

∠1 = ∠5 & ∠5 = ∠7

∠6 = ∠2 & ∠6 = ∠8 and so on

Only two distinct angles are formed

∴ Option (a) is correct.

Answer: (b)

Total surface area of the remaining solid = Curved surface area of the cylinder + Area of the base + Curved surface area of the cone

= 2πrh + π $r^2$ + π rl

= 2π × 8 × 15 + π × $(8)^2$ + π × 8 × 17

= 240π + 64π + 136π

= 440 π $cm^2$