Basic Numeracy MCQ — 3132 Practice Questions with Answers

Explanation

Original total score = mean × number of players = 18 × 10 = 180. Sunita's score was short by 22 - 12 = 10. Corrected total = 180 + 10 = 190. Corrected mean = 190 ÷ 10 = 19. The mean increases by 10 ÷ 10 = 1, so it becomes 19. A common error is to add the full difference 10 directly to the mean.

Explanation

From the chart, March grocery spending is 7 thousand ₹ and March electricity spending is 5 thousand ₹. Total spending = 7 + 5 = 12 thousand ₹. The correct total is 12 thousand ₹. A common trap is to read February electricity or April grocery instead of the March bars.

Explanation

Total expenditure = price × quantity. Let the old price and quantity both be 100 units in index form, so old expenditure = 10000. New price index = 125. New expenditure is 5% higher, so it is 10500. New quantity index = 10500/125 = 84. Quantity fell from 100 to 84, so the decrease is 16%. The reduced quantity must offset most of the price rise while still leaving a 5% higher bill. The common trap is reducing quantity by 20%, which would keep expenditure unchanged after a 25% price rise.

Explanation

Let each annual instalment be x. The present value of the two instalments must equal ₹4,200: x/1.10 + x/(1.10)^2 = 4200. Multiplying by 1.21 gives 1.1x + x = 4200 × 1.21 = 5082. So 2.1x = 5082, hence x = 5082/2.1 = ₹2,420. Equal instalments are found by equating their present values to the loan amount. Simply adding 2 years' simple interest and halving gives ₹2,520, which ignores the timing of payments.

Explanation

At most one elder means either 0 elders or 1 elder. Case 1: 0 elders, so choose all 3 helpers from 4 cousins: 4C3 = 4. Case 2: 1 elder and 2 cousins: 3C1 × 4C2 = 3 × 6 = 18. Total groups = 4 + 18 = 22. The answer is 22 because both allowed cases, 0 elders and 1 elder, must be added. The main trap is reading 'at most one' as 'at least one', which gives 31.