average Model Questions & Answers, Practice Test for ibps so prelims

Answer: (a)

$nz – x + x^1 = nz^1$ Simplify to get option (a) correct.

Answer: (b)

Let average weight of girls = x

Total weight of the boys = 40 kg × 15 = 600 kg.

Average weight

= $\text"Total weight of girls + Total weight of boys"/\text"No. of boys + No. of girls"$

⇒ 38.4 = ${600 + 10 × x}/{15 + 10}$

⇒ 38.4 = ${600 + 10x}/25$

⇒ 38.4 × 25 = 600 + 10x

∴ x = 36 kg

Answer: (c)

Mean salary of the remaining 20 workers

= ${75 × 5680 - 25 × 5400 - 30 × 5700}/20$

= ${15 × 5680 - 5 × 5400 - 6 × 5700}/4$

= 15 × 1420 – 5 × 1350 – 6 × 1425

= 15 [1420 – 450 – 2 × 285]

= 15 [1420 – 450 – 570]

= 15 × 400 = 6000

Answer: (d)

Let the five consecutive even numbers be

x, x + 2, x + 4, x + 6 and x + 8 respectively.

According to the question,

x + x + 2 + x + 4 + x + 6 + x + 8 = 5 × 52

or 5x + 20 = 260

or 5x = 260 – 20

or $x = 240/5$ = 48

∴ B = x + 2 = 48 + 2 = 50

and E = x + 8 = 48 + 8 = 56

∴ B × E = 50 × 56 = 2800

Answer: (a)

Average score

= $1/6 [221 + 231 + 441 + 359 + 665 + 525]$

= $1/6 [2442] = 407$